96' Avenger Brake Lights?

1996 Dodge Avenger ES, v6, automatic. Recently, brake lights won't turn off even when the car is off and keys out of ignition. We have replaced the switch at the brake pedal, and it worked perfect (that is that the brake lights turned off when car was off), however the next morning our car was dead.
We suspect this switch is draining our battery (because the battery is brand new), but we don't know where to look in the wiring. Would it even be in the wiring? We have replaced all three relays under the hood on the firewall in 2011.
For now, we have no brake lights again (because we unplugged the switch so the car won't be dead when we go to leave), but we do have all other lights such as reverse, running, parking, and turn signals(no interior though). Please help us find the source.