Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to wire a breaker circuit [title] Switch off the main power switch. [step] This should be located at the top of the breaker panel. [title] Take the cover of the breaker box off.

Ending1: [title] Notice there is a small grey panel with a screw inside that turns in a switch. [step] This can be simply screwed aside or left alone. Ending2: [title] Use an electrical tester by putting the tip of one probe against the ground bus bar and the other against one of the screws of a circuit breaker. [substeps] Connected to this screw should be a red, black, or blue covered wire. Ending3: [step] At the top of the panel, there will be about a half inch area of insulation. It's important that you wrap the insulation around the cover that goes inside of it. Ending4: [step] Start by pressing and then releasing the button. [title] Cut the insulation from the back of the switch.

Answer format: ending1/ending2/ending3/ending4