For vehicles with automatic transmission, the brake lights switch may allow grease on the brake pedal bracket and rust proofing oil on the return spring to enter inside due to the improper manufacturing method, and these substances may carbonize and cause the electrical resistance to increase. If the vehicle continues to be driven with such an electrical problem, (1) the shaft in the switch may deform and stop functioning, which will make it impossible to release the shift lock, and/or (2) the brake lights may fail to illuminate.