I woulod think that there is a an adjustment screw near the pedal, next to engine behind the bracketry. I looked at mine, looks like a serated nut that holds the switch, maybe allow the swithc to drop down to give it more slack?
I agree with Redryder. I just had the same issue. Behind the sheet metal cover plate by the pedal there is a switch. It kinda just sits in its little hole with an adjustment nut on top of its bracket. Adjust the nut UP to allow the switch to slide DOWN a little. It's a tight fit for the fingers and you may want to recruit your wife or someone with smaller fingers to help.
Your brake switch should be right there by either your floor board assembly or your peg assembly depending if you have the "C" or Retro. Once you find your switch then you should find the lock or jam nut, loosen it and then make you adjustment. Tighten the nut back up and give your brakes a try. I believe the service manual says to have the brake light come on just before the brake pads begin to engage the rotor.