Wiring the round AutoZone LED rocker switches

There are tiny numbers 1, 2 & 3 next to the solder terminals on the back of the switch.

Terminal 3 is a bronze color, while 1 and 2 are more silver color.

Terminal 3 is common ground (negative).

Your battery +9v (or +12v) supply goes to terminal 2. Do not send more than 12v through the switch or the LED will burn out.

Your switched output (to the + input to your dome PSI lights or whatever you are controlling) goes to terminal 1.

The built-in LED has an internal limiting resistor and gets its power from terminals 2 and 3.