Wondering what's going on in the walls?
How power gets to your lights, in plain English
Power takes a trip to reach your light. It starts on a pole outside and ends at the bulb. A flicker means something along the way isn't holding steady. It's a bit like a garden hose: a kink anywhere, from the faucet to the nozzle, makes the water sputter.
- The pole and the transformer. Power comes down the street on wires up high. A gray can on the pole, called a transformer, turns it down for your house. Several houses often share one. So a problem here can make the neighbors' lights flicker too.
- The wire to your house and the meter. One wire runs from the pole to your house and into the electric meter. The power company usually takes care of this part. CPSC says flicker that gets worse in the wind can come from a bad connection here.
- The breaker panel. Inside, power goes into the panel. Each breaker sends it out to one circuit, a group of lights and outlets.
- The circuit and the switch. Wires run inside the walls to a switch, then on to the light. A loose wire anywhere on the circuit can make lights flicker, often more than one.
- The bulb. The last stop. When just one light flickers, it's often the bulb. It may be loose or worn out, or it's an LED on the wrong dimmer (This Old House, Bob Vila).
So where's your flicker coming from?
- One light: usually the bulb, the dimmer, or that light's switch.
- Several lights in one room: usually something on that circuit.
- Only when the AC or fridge starts: a quick dip is normal. A big one isn't.
- The whole house: the power coming in, at 1 or 2.
The questions at the top check them in that order, safest first. Lights flickering and a breaker tripping too? See our guide to a breaker that keeps tripping. A warm or scorched outlet? See an outlet that's not working. Lights dim hard when the AC starts? A worn start-up part in the AC can do that. See an AC blowing warm air.
Rather not do it yourself? Call an electrician.
That's a fine choice. Maybe you're busy. Maybe you're selling the house and just want it done right. An electrician can find a loose wire or a worn switch and fix it safely.
Most electricians charge $50–$130 an hour, and many charge a $100–$200 service call that covers the first hour. If the whole house flickers, call the power company first. That's usually free.
Find electricians near you
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What to say
Calling a pro? Here's what to say.
A few lines to read when they pick up, and the questions to ask before anyone comes out.
Before you call
Say this
Hi. The lights in my house keep flickering. When's the soonest you can get here? And what's your fee for the visit? Does it go toward the repair?
Always ask
- What's your fee to come out, and does it cover the first hour?
- Do you charge by the job or by the hour?
- Will you tell me the full price before you start any work?
Watch out if
- They push rewiring the whole house on the first visit for a small problem.
- They can't show you a license number.
- They won't give you a price before starting.
Feeling pushed to decide on the spot? You can say no and hang up. You owe nothing for a phone call.
Answer up to 5 quick questions. We'll give you the words a pro uses.
Answer the questions →More of a list person?
Common flickering-light problems, causes, tests and costs
Find the row that sounds like yours. The quick test is something you can check safely in a few minutes.
| What you notice | What it probably is | Quick test | Do it yourself | With a pro | Verdict |
|---|---|---|---|---|---|
| Burning smell, buzzing, sparks, or a hot or scorched switch | Danger signs at a light, switch or outlet | Look, listen and sniff from a step back. Don't touch | Pro job | $80–$200 | CALLSee the answer: Danger signs at a light, switch or outlet |
| Some lights get brighter while others get dimmer | Lights going bright and dim | Watch a few lights in different rooms at once | Pro job | $100–$200 | CALLSee the answer: Lights going bright and dim |
| Your lights and your neighbors' flicker, on a calm day | A problem on the power company's side | Ask a neighbor, or look at the houses nearby | Pro job | $100–$200 | CALLSee the answer: A problem on the power company's side |
| Lights blink in a storm, and the neighbors' do too | Short blinks from the power lines, in a storm | Look at nearby houses and streetlights | Free | Not needed | FIXSee the answer: Short blinks from the power lines, in a storm |
| Lights all over the house flicker, worse in the wind. The neighbors are fine | A loose connection where power comes into your house | Look at the wire to your house from the ground | Pro job | $100–$200 | CALLSee the answer: A loose connection where power comes into your house |
| One light flickers. Tightening the bulb fixes it | The bulb is loose | Let it cool, then twist it snug | Free | Not needed | FIXSee the answer: The bulb is loose |
| One light flickers. A new bulb fixes it | The bulb is going bad | Put in a new bulb of the same type | Free | Not needed | FIXSee the answer: The bulb is going bad |
| LEDs on a dimmer flicker, often when turned down low | The LED bulbs and the dimmer don't get along | Check the bulb for "dimmable," then slide the dimmer up and down | Free | Not needed | FIXSee the answer: The LED bulbs and the dimmer don't get along |
| LEDs flicker on an old dimmer, even with dimmable bulbs | An old dimmer that isn't made for LEDs | Look for "LED" on the dimmer | Pro job | $80–$200 | CALLSee the answer: An old dimmer that isn't made for LEDs |
| A tube light flickers when it's cold, then steadies | It's cold, or still warming up | Let it run a few minutes | Free | Not needed | FIXSee the answer: It's cold, or still warming up |
| A tube light flickers. A new tube fixes it | A worn-out tube | Put in a new tube of the same length and type | Free | Not needed | FIXSee the answer: A worn-out tube |
| A tube light still flickers, hums or starts slowly with a new tube | The ballast is wearing out | Try a new tube first | Pro job | $75–$150 | CALLSee the answer: The ballast is wearing out |
| The light flickers when you touch the switch. It feels loose or mushy | A worn-out wall switch | Flip the switch gently a few times | Pro job | $100–$203 | CALLSee the answer: A worn-out wall switch |
| One light flickers with a new bulb. The socket may look dark or loose | A loose wire in the light or its switch | Try a new bulb, then flip the switch gently | Pro job | $100–$200 | CALLSee the answer: A loose wire in the light or its switch |
| Lights flicker when something big runs nearby | Too much is plugged into one circuit | Turn off the big thing and watch the lights | Free | Not needed | FIXSee the answer: Too much is plugged into one circuit |
| Several lights flicker at random, maybe with a breaker tripping | A loose connection on the circuit | Watch with nothing big running | Pro job | $100–$200 | CALLSee the answer: A loose connection on the circuit |
| Lights dip for less than a second when the AC or fridge starts | A quick dip when a big appliance starts | Count how long the lights stay dim | Free | Not needed | FIXSee the answer: A quick dip when a big appliance starts |
| Lights dip hard or stay dim when the AC, fridge or dryer starts | Big dips when a big appliance starts | Count how long the lights stay dim | Pro job | $100–$400 | CALLSee the answer: Big dips when a big appliance starts |
2026 U.S. averages, rounded. Pro prices include parts and labor. Most electricians charge $50–$130 an hour, and many charge a $100–$200 service call that covers the first hour. Nights, weekends and big cities cost more. See all repair prices
Want proof it's the bulb, not the wiring?
The new-bulb test
This one test sorts out most single flickering lights. This Old House and Bob Vila both start here.
- Turn the light off. Let the bulb cool for a few minutes.
- Twist the bulb in until it's snug. Turn the light on and watch for a minute.
- Still flickers? Put in a new bulb of the same type, and no more watts than the fixture's sticker says.
- Flip the switch gently a few times.
- Tightening or a new bulb fixed it: it was the bulb. You're done.
- It flickers when you touch the switch: the switch is probably worn. Call an electrician.
- A new, tight bulb still flickers: a wire in the light or switch is probably loose. Leave it off and call an electrician.
On a dimmer? Slide it all the way up first. If it only flickers down low, it's probably the bulb and the dimmer not getting along.
Are flickering lights dangerous?
Turn it off and call right away if…
Most flickering lights are a bulb or a dimmer. These signs are not:
- You smell burning or hot plastic.
- You hear buzzing, sizzling or crackling at a switch, light or outlet.
- You see sparks, or a switch or outlet is too hot to touch or scorched.
- Some lights get brighter while others get dimmer. Call your power company now, and unplug electronics you can reach safely.
- A tube light has burn marks or an oily leak.
- A wire outside is down, sagging or sparking. Stay at least 35 feet away and call 911.
For a hot or buzzing switch, turn off its breaker if it's safe, and call an electrician today. If you see smoke or flames, get everyone out and call 911 from outside.
Got an electrician's quote?
What a fair price looks like
Most flickering lights cost nothing: a loose bulb, a new bulb, or a dimmer setting. Problems on the power company's side are free to you. When you need an electrician, here's what's fair:
- A service call: HomeAdvisor lists $100–$200, which covers the first hour. After that, $50–$130 an hour.
- A new light switch: HomeAdvisor lists $100–$203 installed, about $152 on average. Fixr lists less, $50–$75.
- A new dimmer: HomeAdvisor lists $80–$200 installed. Fixr lists $75–$100.
- A new ballast for a tube light: HomeAdvisor lists $75–$150. Ask what an LED fixture would cost too.
- Fixing a light fixture: HomeAdvisor lists $100–$200 plus parts.
Example: $150 to replace one worn switch is fair. Being told you need the whole house rewired because one light flickers is worth a second opinion.
Ran into a word you don't know?
Electrical words, explained
Read these before you start. The drawings show roughly what each part looks like.
- Light fixture
- The light itself, on the ceiling or wall, that the bulb screws into.
- Socket
- The part of the fixture the bulb screws into.
- LED bulb
- A bulb that uses little power and lasts a long time. Most say "LED" on the base.
- Dimmable
- Printed on bulbs that can be dimmed. Only these work well on a dimmer.
- Dimmer
- A wall switch with a slider, knob or rocker that turns lights up and down.
- Low-end trim
- A setting on many LED dimmers that sets how low the lights can go. Raising it can stop flicker.
- Wall switch
- The switch on the wall that turns a light on and off.
- Fluorescent tube
- A long, skinny tube light, often in garages, kitchens and basements.
- Ballast
- A box inside a tube light's fixture that starts and runs the tubes.
- Circuit
- One loop of wiring from a breaker to a group of lights and outlets.
- Breaker (circuit breaker)
- A safety switch in the panel. It flips off when too much power flows through one circuit.
- Breaker panel
- The metal box, often in a garage, basement or closet, where all the breakers are.
- Overload
- More power running on one circuit than it's built for.
- Transformer
- The gray can on a power pole. It turns the power down for houses nearby.
- Service drop
- The wire that runs from the pole to your house.
- Electric meter
- The round meter on your outside wall. Power goes through it on the way to your panel.
- Neutral
- The wire that carries power back. If it comes loose, some lights go bright and others go dim.
- Capacitor (start-up part)
- A small metal can in an AC that gives the motor a push to start.
- Scorch marks
- Black or brown marks around a switch or outlet. They mean something got too hot.
Still have questions?
Questions people ask most
Are flickering lights an emergency?
Flickering lights are an emergency if you smell burning, hear buzzing or crackling, see sparks, or a switch feels hot. Turn off that breaker if it's safe, and call an electrician today. Lights getting brighter and dimmer is an emergency too. Call your power company now. A light that flickers now and then, with none of those signs, can wait for the checks above. Smoke or flames? Get everyone out and call 911 from outside.
Why are my lights flickering in the whole house?
Lights flickering all over the house usually point to a problem with the power coming in, not one light. First, ask a neighbor. If their lights flicker too, call your power company. If it's just your house, call the power company anyway. Then call an electrician if they say their side is fine.
Why do my lights dim when the AC turns on?
A quick dip when the AC starts is normal, because the AC pulls a lot of power for a second (Bob Vila). A dip that's big, lasts a few seconds, or keeps getting worse isn't normal. It can be a loose connection (This Old House) or a worn start-up part in the AC. Call an electrician, or an AC tech for the AC.
Why do my LED lights flicker?
LED lights usually flicker because they're on a dimmer that wasn't made for them, or the bulb isn't marked "dimmable" (Bob Vila, Leviton). A loose or worn-out bulb can flicker too. Try a new dimmable bulb first. Still flickers on every setting? The dimmer may need replacing.
Why do my lights flicker on a dimmer switch?
Lights that flicker only when the dimmer is turned down low often can't dim as low as the dimmer goes (Lutron). Most LED dimmers have a lowest-level setting you can raise. Follow your dimmer's instructions. An old dimmer made for regular bulbs may need to be swapped for one made for LEDs.
Why are my fluorescent lights flickering?
A fluorescent light that flickers is often just cold, warming up, or has a tube that's wearing out (Bob Vila). Try a new tube of the same size and type. If it still flickers, hums or starts slowly, the ballast inside is probably wearing out (LEDVANCE). That's a job for an electrician.
Why do my lights flicker during a storm?
Short blinks during a storm usually come from the power lines, not your house. Wind can push branches into the lines (FPL). Then the power company's equipment cuts power for a moment to protect them (LG&E and KU). Still flickering after the storm, or only your house? Call your power company. A branch may have hit the wire to your house.
Why are my lights dimming and brightening?
Lights that get dimmer and brighter at the same time can mean a lost neutral. That's a loose wire where power comes into your house. It's dangerous. Some things in the house can get too much power. That can ruin electronics and start a fire (Fine Homebuilding, Hunker). Call your power company now. Unplug electronics you can reach safely.
Can flickering lights cause a fire?
Flickering lights can be a sign of a loose connection, and a loose connection can overheat and start a fire. Bob Vila says popping or crackling means sparks are jumping inside. A loose bulb or a dimmer mix-up isn't a fire risk. A burning smell, buzzing or a hot switch is. Call an electrician.
Why is just one light flickering, like in the bathroom or on a ceiling fan?
When just one light flickers, start with the bulb, because it may be loose, worn out, or not made for that dimmer (This Old House). Tighten it, then try a new one. Still flickers? The switch or a wire in the light may be loose. Call an electrician, and don't open the fixture.
Who do I call for flickering lights?
Call a licensed electrician for flickering in one room, a switch that's warm or mushy, or a light that flickers with a new bulb. Call your power company first if the whole house flickers, the neighbors' lights flicker too, or lights go brighter and dimmer. Try the free checks first: tighten the bulb, try a new one, and check the dimmer. Renters should tell the landlord.
How much does it cost to fix flickering lights?
Fixing flickering lights is often free, if it's a loose bulb, a new bulb, or a dimmer setting. Problems on the power company's side are free to you too. An electrician's visit is about $100–$200 for the first hour (HomeAdvisor). A new switch is about $100–$203 installed, and a dimmer $80–$200 (HomeAdvisor). Fixr lists less.
How we built this
The questions follow the order an electrician checks flickering lights: danger signs first, then how many lights flicker, then the bulb, the dimmer and the switch for one light, the circuit for one room, and the power coming into the house for the whole house. Each answer makes some causes more likely and others less likely.
Prices are 2026 national averages from published repair-cost guides, rounded. Your local prices will differ.
- U.S. Consumer Product Safety Commission, CPSC guide to home wiring hazards (undated, about 2001, read October 2026)
- U.S. Consumer Product Safety Commission, National Electrical Safety Month notice (undated, read October 2026)
- Bob Vila, flickering lights: causes and fixes (updated December 2024)
- This Old House, how to fix flickering lights (October 2024)
- Fine Homebuilding, lights that dim and brighten, answered by an electrical contractor (undated, read October 2026)
- Hunker, what causes lights to dim and then brighten? (updated September 2022)
- FPL, power flickers (undated, read October 2026)
- LG&E and KU, why are my lights flickering? (April 2026)
- Puget Sound Energy, downed power lines (undated, read October 2026)
- Lutron, flickering or flashing lights with Caséta dimmers (undated, read October 2026)
- Lutron, ghosting or blinking LED lights with Maestro dimmers (undated, read October 2026)
- Lutron, why a dimmer feels warm (undated, read October 2026)
- Leviton, how to avoid flickering LED lights (August 2025)
- Leviton, why does my LED bulb flicker or turn off when dimming? (January 2026)
- Family Handyman, how to replace a fluorescent light ballast (updated December 2024)
- LEDVANCE, how to check if the ballast is bad in a fluorescent light (undated, read October 2026)
- U.S. EPA, recycling and disposal of CFLs and other bulbs that contain mercury (updated November 2025)
- R.F. Ohl, why are my lights flickering when my AC turns on? (July 2023)
- HomeAdvisor, cost to hire an electrician (June 2026)
- HomeAdvisor, cost to replace a light switch or dimmer (June 2026)
- HomeAdvisor, cost to repair or replace a light fixture, including ballasts (June 2026)
- Fixr, cost to install a light switch (January 2025)
- Bob Vila, cost to replace a light fixture (November 2023)
- HomeGuide, electrical outlet repair cost (September 2025)
- Fixr, AC repair cost guide (July 2026, for the AC start-up part)
- HomeServe, HVAC repair costs (March 2026, for the AC start-up part)
How we make money: some links go to parts stores that pay us a small commission, and some pro listings pay us when you call them. Verdicts come from the diagnosis, not from who pays more.