Turn Off the Power
Before you begin any electrical project, go to the electrical panel and shut off the circuit that you’ll be working on. Sometimes, not always, the electrician will mark the panel, on the inside of the door with the location the each individual breaker supplies. If it is marked, turn off the correct circuit. If it is not marked, plug something into the circuit and one-at-a-time start shutting off breakers. When the device that you plugged in goes out, you may have found the circuit.