An electrical receptacle should not make an audible buzzing sound during normal use. Noise, heat, odor, discoloration, or crackling can indicate a loose connection, worn contact, electrical arcing, or a faulty appliance plugged into the outlet.
Unplug the load if it is safe to do so
If the receptacle is not hot or distorted and the plug can be removed safely, unplug the appliance and see whether the sound stops. If the outlet is hot, smells burned, or is arcing, do not continue handling it.
Check whether the noise continues with nothing plugged in
Buzzing that stops may be coming from the charger or appliance, although the receptacle still deserves attention if it feels loose or warm. If the sound continues with nothing connected, the outlet or its wiring is more likely involved.
Do not remove the cover plate or tighten live connections
A loose connection can generate heat and arcing even while the outlet still works. Turn the circuit off at the panel if you can identify it safely and leave internal inspection to an electrician.
Heat or visible damage means leave the circuit out of service
Scorched plastic, discoloration, poor plug retention, or recurring noise are reasons not to use that receptacle again until repaired. If smoke or fire is present, leave the area and call emergency services.
Sources
- U.S. Consumer Product Safety Commission — Electrical Safety — Household electrical hazards and safe response to overheating, outlets, switches, and breakers.