Park brake indicator on acceleration

I am having a problem with my parking brake indicator light comming on durring acceleration. To see if it is the switch I disconected it at the parking brake. Now the light does not come on with the brake engaged but will still come on durring acceleration. It will go out if I let off the accelerator for a period of time (not a fixed period) or if I let off the pedal and tap the brakes. I had been having electrical problems but those were fixed whith a new battery and engine ground. Both are now very nicely grounded as I ground off the paint to bare metal and used thicker wires. The park brake indicator problem had started before the other problem so it is hard to say if they are related.

I am assuming that there is some control unit that is resposible but I do not know the electrical system well enough to know which and where to find it. I little help would be greatly appreciated.

Note: I have tested the brake fluid and inspected pads and roters, all checked out fine.

Two things and both are contacted.

1)Check you brake fluid resv. level. If it is low, just add some brake fluid and the problem will go away.

2) Master cylinder cap, check to see if the float, um, floats.

Thank you so much for that tip. It was inded the float. Some debris had gotten lodged in there so I flushed the master cylinder and cleaned the float. That solved my problem. No more embarrasment driving arround with a parking brake light on,