A circuit map tells which circuit breakers or fuses control which outlets; it can help locate wiring problems and prevent overloads. Draw a floor plan of each story, showing outlet and light fixture locations. Stick numbered labels beside all breaker switches or fuses except the Main (the largest one), which shuts off all power. (Breakers or fuses may already be numbered on the door panel.)
Turn on all light fixtures and plug all outlets with lit lamps. As you switch off each breaker or unscrew each fuse, have a helper tell you which lights go out. On your map, number the outlets by their breaker or fuse numbers. Put the plans in an envelope and post near the service panel.