Z3 Roadster (E36/7) Mystery switch/sensor

I removed the interior console from my '97 Z3 1.9L and found a switch/sensor that was not attached to anything. It is square, measuring approx 1 5/8" X 1 1/2" X 1/2". It has a square hole with a metal strip at the bottom of the hole and attaches to 2 wires. It is numbered 8 366 215 and is a BMW part. Does anyone know what it is and to what it may attach?
Thanks for any help!

I assume you are talking about a device that is behind the radio. In that case, it is part of the anti-theft system. As I recall, the head unit had a pin that fits in the hole and closes the contacts. If you have an after-market head unit, it has no function. I removed mine to create more room for the wire harness.

That's it! Thank you