Heat or smoke near outlets, switches, wiring or the electrical panel.
Electrical odors can travel through wall cavities, making the strongest-smelling room different from the source. If the correct breaker can be reached safely, switch it off and leave the damaged equipment untouched.
Smoke near service equipment can involve high-current connections that should not be approached or opened. If the correct breaker can be reached safely, switch it off and leave the damaged equipment untouched.
Buzzing or crackling together with a burning smell raises concern for a loose or arcing connection. If there is active fire, heavy smoke or immediate danger, move to safety and call 911 first.
