Outlet or switch makes a buzzing sound

Symptoms

• Faint or noticeable buzzing or humming from the wall
• Buzzing changes when a dimmer or switch is adjusted
• Sound is louder near one specific outlet or switch

Likely causes

• CommonA loose wire connectionLoose connections arc slightly under load, which can sound like a buzz or hum.
• CommonAn incompatible or failing dimmer switchDimmers not rated for the bulb type, especially LEDs, commonly buzz.
• PossibleA worn-out switch mechanismOld toggle or rocker switches can develop an audible hum as contacts wear.
• PossibleA loose or degraded outlet receptacleWorn contact springs inside an outlet can buzz when a plug is inserted.
• PossibleA failing appliance plugged into that outletSometimes the buzz is actually the transformer or motor of whatever's plugged in.

What to do

1. Unplug anything connected to the buzzing outlet to see if the sound stops.
2. If it's a switch, check whether it's a dimmer and confirm the bulbs it controls are dimmer-compatible.
3. Try swapping to LED-compatible dimmer-rated bulbs if the buzz only happens while dimmed.
4. Turn off the breaker for that circuit before removing the cover plate to inspect connections.
5. Look for any discoloration, melted plastic, or loose wires at the terminals.
6. If wires look loose, that's a sign for a professional to tighten or replace the device, not a DIY fix unless you're experienced.
7. Replace an old, worn switch or outlet if it still buzzes with nothing else plugged in and no obvious fault.

Tools and parts

• Non-contact voltage tester
• Screwdriver

When to call a pro

Call an electrician if the buzzing is loud, continues after unplugging devices, or you find loose or discolored wiring inside.

Safety