One of these is the power feed and one is the switch leg but the switch terminals are interchangeable so there is no need to identify which is which.
Electrical wall switch installation.
Still you will want to replace a switch when it wears out in part because it presents a fire hazard.
To replace this kind of switch follow these steps.
Circuit electrical wiring enters the switch box.
Turn off the power to the switch at the main circuit breaker or fuse panel.
Unscrew the switch from the electrical box and pull it out with the wires still attached.
Explanation of wiring diagram 1.
Switch wiring shows the power source power in starts at the switch box.
This is an updated version of the first arrangement.
Then use a voltage tester to make sure that the circuit is dead.
Most of the common types of switches come in different styles such as toggle rocker slider or push.
One of these will likely be black.
The red and black are used for hot and the white neutral wire at the switch box allows for powering a timer remote control or other programmable switch.
There should be one wire only under each terminal.
The other may be black red or white.
Electric wall switches last a long time.
Featuring wiring diagrams for single pole wall switches commonly used in the home.
The black wire power in source attaches to one of the switch screw terminals.
Unscrew and remove the switch plate.
Disconnect the old switch wiring.
The wall switch is one of the most common and important electrical devices in the home.
You may want to change the size color or style of the switch.
Another reason to change out the switch is appearances.