brakes squeeking and now the brake light on the dash is coming on

Something tells me that this is most likely something dumb, like the I need to change the brakes or the master cylinder...but I figured I would run this past the pro's on here first.

Anyways, I noticed the brakes start squeaking the other day on my 1972 Dart Swinger. Today, I went for a short cruise and when I would come to a stop at a stop sign, the light will come on briefly. It seems like the pedal is basically going all the way to the floor as well. Any thoughts?