I have a back room that was converted from a back porch to a room. It has a light switch on one wall that doesn't appear to work anything. I checked to see if it has current coming to the switch and it was showing less than 1 volt. The switch is very old and has 2 red wires and 2 black wires coming to and going away from it. How do i safely eliminate this switch? I do not want to replace it with another. I just want it gone.
Shut off power and trace the cables leaving that box. (See How to trace mystery switches.) Once you've identified the cables and confirmed they're truly not connected to anything else, you can cap them in the box or cut them back (see What is the proper way to leave unused nonmetallic sheathed cable inside walls or ceilings?), remove the box, and patch the wall.
Turn off the power at the circuit breaker for safety. Cap all wires with a wire nuts. Replace with blank faceplate and then turn the power back on.