This gauge is when you want to use the quick connect method when wiring a light switch. In this picture you can see the strip gauge on the back of the switch.
Smart Light Switch Wiring Diagrams Mr Electrician
How light switches are wired. You should see two black wires each connecting to a different screw on the right side of the switch. The other terminal is marked as l1 and is the output to the light fixture. Simply strip the wire to the length specified and push the wire into the hole. At the light the white wire connects to the neutral terminal and the black wire connects to the hot. The neutral wire from the source is spliced to the white cable wire and continues on to the light. In this illustration you can see the red hot lead wires of the dimmer are connected to the inbound black wire from the electrical source the electrical panel and the black wire that goes to the light fixtures black wire which in this case is a white wire that has been taped with black electrical tape.
These are called terminal screws. The source is at the switch and 2 wire cable runs from there to the light. The source hot wire is connected to a switch terminal and the other terminal is connected to the black cable wire. Connect the source wire to the bottom terminal of the switch and the other black wire to the top terminal. The common is for the live wire that supplies the input voltage to the switch. A dimmer switch is wired the same way as a single pole switch.
Basic knowledge of how to wire a light switch black wire this is the hot or load wire white wire this is the neutral wire bare copper green wire this is your ground wire red wire this wire is used for 3 or 4 way switches and will connect the switches together so they can each control. A one way light switch has two terminals which is a common marked as com or c. You should also see a green wire called a ground wire which.