HELP! What the heck is this?

I took and tossed the one from my 1974 Valiant the day after I got it (new in 1974 that is). If I remember right - if you just unplugged it, and I think you had to jumper one wire - not sure about the - you did not need it. It was a real pain car would not start if there was a package laying on the passenger side of the seat. My wife and I both wore belts then and just thought it was a stupid idea to make it impossible to start the car without fastening the buckles.

On the dash lights going out, the most likely candidate is the resistor on the headlight switch. The contact probably broke off or burned off. They were known to fail.