Vintage 60's 70's Guitar Amplifier Reverb Pedal Big Foot Switch or Car Auto 

OK, as it sits, it is some kind of switch, the button clicks when depressed,  the cord is brittle and the connector needs fixing.

Pedal is the right foot, where the others I see are left.

There are screw holes in the back, so it can be adapter to a car or left alone and be used w a guitar. 

I loosened the screws to separate the pedal for photos and shipping.