Your description is dandy. The only other switch is part of the combination valve near the master cylinder. It turns on when there is a leak in one half of the hydraulic system. Normally the light turns WHILE you're pressing the brake pedal, but if it tripped recently, it can do what you're describing.
Before you go searching for that switch, and assumming nothing changes when you play with the parking brake, unplug the switch from the master cylinder reservoir while the light is staying on. If the light goes out, if the fluid isn't low, check the styrofoam float to see if it's sinking.
Thursday, March 11th, 2010 AT 7:50 PM