I found this under the passenger seat of my 2001.5 Passat while lubing up the locking pin in the slide. It could be from the seat or it could be from somewhere else in the vehicle and at some point got tossed under there.
It’s some sort of microswitch with the little metal part moving. There’s the wire harness connector that has a VW symbol and part number, but the part number is just for the electrical connector, not the switch. The switch had a date code and the name Burgess on it, but mnopart number. There are also two small posts on the switch body to mount it.