its an amp switch for the factory radio. kinda like a boost. If you dont have the factory radio you can get rid off it. If you do have a factory radio, while its on, push the knob for it and see if it still works
Yes, factory Ford amp. Probably more trouble to try and use it than it would ever be worth. Should be able to remove both the switch, the amp, and a bunch of wiring.
Maybe keep it for when people try to resto these things.