Montego,Brake sensor is to sensitive causing brakes to flicker while driving. 2005 Mercury Montego

My brake light sensor for my brake pedal is to sensitive or my brake pedal is too loose (it doesn't feel to loose). This causes my brake lights to flicker (tail lights) to flicker when I'm driving (as if I'm tapping the brake pedal). It comes on and doesn't flicker when I actually press the brake pedal and if I pull up on the brake pedal while I'm driving it doesn't flicker either. The brake pedal appears to rest right at the point that triggers the lights. Therefore every little bump in the road or anything cause the brake lights to flicker. How would I fix this? Than