The Nissan Path

Help, the parking Brake light on my 98 Pathfinder SE comes on whenever it pleases. The brake works fine, and so does the switch below the brake handle. Originally it started coming on when it got cold, and now it seems to come on randomly with motion, almost like something is loose and rattling back and forth.

I have re-seated the Brake reservoir low fluid sensor plug, but the light still comes on.

Any help would be appreciated.