Volkswagen Golf Brake Light Switch Problems

the large STOP warning light comes on after braking and the pedal is released.This does not happen every time I brake.I've spoken to a vw mechanic and he along with a few other mechanics suggested it could be the expansion bottle level sens...

Front and rear doors lock stuck in locked position, I renewed both locking mech and back door is now fine but front door still not working, ie stays locked when operated in any way key/fob.. I welcome your ideas, thanks in advance..