Replacing 60-year old light switch - which wires go where?

Question

A light switch in my house won't go to the off position, so I need to replace it. Every direction I've read about how to do this says to keep the wires in the same configuration (top, bottom, ground), but the old switch is strange, and I don't see anything about this configuration.

I have attached some photos. There are three wires attaching to two spots on the switch. On the left side, two black wires are both attached to the same point, and on the right side, one red wire is attached.

Any thoughts on which wire should go where would be appreciated.

If more information about where the wires are each coming from would be helpful, please let me know, and I would be happy to give more detail.

Thanks!

Robert

Answer 1

Based on the photograph, I'd say the black wires are feeding voltage from the panel (hot) and carrying the voltage onto another switch or outlet. The red wire is presumably going to the light (load).

You need to connect the black wires to one screw of the new switch and the red to the other. Leave the green (ground) screw unconnected.

It's generally not good to put two wires under one screw as was previously done. Better to add a pig-tail: a third short wire to the switch. Connect the two blacks and the other end of the pigtail together with a wirenut.