A fishy odor with no cooking can come from trash, drains, or organic material, but it can also come from overheating plastic or electrical components. If the smell is strongest near an outlet, switch, light fixture, panel, or appliance and there is heat, discoloration, or crackling, stop using that area and treat it as an electrical problem.
Narrow down the odor without taking anything apart
Walk through the home and note where the odor becomes stronger while checking trash, drains, and appliances from the outside. Do not remove energized outlet or panel covers to get closer to the source.
Heat or discoloration near electrical equipment is a stop sign
If a receptacle, plug, or switch is hot, browned, distorted, buzzing, or crackling, stop using it. Turn the circuit off from a dry, safe location if that can be done without approaching smoke or fire, and call an electrician.
Check organic sources when electrical warning signs are absent
Trash bags, pet areas, forgotten food, and drain buildup can create strong odors. Clean the identified source and ventilate, but do not use fragrance to mask an odor whose origin is still unknown.
A recurring odor with no visible source deserves investigation
An intermittent smell that coincides with heating, lights, or appliance use can be a clue to overheating. If you cannot isolate it safely, stop using the suspect circuit or equipment until it is checked.
Sources
- U.S. Consumer Product Safety Commission — Electrical Safety — Household electrical safety, overloads, damaged connections, and warning signs to stop use.