Backup switch on jetta'92

Good day all:

Backup light on my jetta is not working I checked thr fuse and the light bulb and they are ok. I am suspecting that the switch is at fault. The question is where is it located? Thx!!

Auto or manual? Both are on the transaxle.

Thanks for your help. Took it out and cleaned it and it is working again. Thanks boschmann