I have 86 16V and need a little help.

The fuel gauge keep jumping around, and I read something about cleaning the switch which located in the trunk behind the carpet area. As I pull the carpet out, just what am I looking at?! a plug? a switch or what? How do I go about clearning it? or do I have to replace it? Anybody have any pic?? Please any help would be very greatful!!

John16V