If you shake the jeep does it rattle? This is pretty far out there but it looks like a shaker switch. Part of an alarm system. the terminal on the top will ground when it is moved. The big problem was that it took 15 minutes to quit shaking so you could set it.
IO---You are the big winner!!! It does rattle. I took it off and I think you are right. I did call my Dad and sent him a pic and he had no clue but said it was definately there when we bought it. Mystery solved