Clicking Coming From dash or Firewall W/braking

Ok....Just bought a 97 lumina. When the car is moving and you touch the brake pedal you can hear a clicking sounds to be high on the firewall or high in the dash. At night the headlights kind of flicker when this clicks. Probably soes in the daytime also just cant notice the flicker. Does any one have any Ideas what this could be. Kind of sounds like a relay of some sort clicking in and out. But since the vehicle has to be moving before it does it prevents me from checking under the hhod to find it.
thanks
joakes

[QUOTE=joakes]Ok....Just bought a 97 lumina. When the car is moving and you touch the brake pedal you can hear a clicking sounds to be high on the firewall or high in the dash. At night the headlights kind of flicker when this clicks. Probably soes in the daytime also just cant notice the flicker. Does any one have any Ideas what this could be. Kind of sounds like a relay of some sort clicking in and out. But since the vehicle has to be moving before it does it prevents me from checking under the hhod to find it.
thanks
joakes[/QUOTE

Mine does the same. You could probably recreate the sound at a stand
still, with the car running by taping the brake pedal to the side. It appears to be the brake light switch.