What is this switch?
This is what the back side should look like.

If there is something to solder wires to and the contacts work it might be worth 1/4 to 1/2 to some one.
If you move the post over you should be able to see the contacts.
In one particular position the contacts on the back should be shorted together.
What I found on my original was the little springs that push down on a bar inside the switch were rusted away so the bar could not make contact.
reverse light switch