But...the most common is the handbrake switch but it can be the fluid sensor too, to rule them out unplug them one at a time and if it stops you know which one is making tricks..
Info from EL.Where is the connection from the handbrake to light up the BRAKE light on the instrument cluster to unplug?
Handbrake and low brake fluid level warning lamp
The handbrake and low brake fluid level warning lamps are connected to the instrument
pack from pin C0230-10 on a KO wire to Header C0293 LHD/C0285 RHD. From header
CO293 LHD/C0285 RHD a KO wire is connected to the handbrake switch, the handbrake
switch is locally earthed.
A second connection from header C0293 LHD/C0285 RHD is connected to the brake fluid
level switch on a KO wire. The brake fluid level switch is earthed on a B wire.
If either of the switches closes, an earth circuit via the closed switch contacts is completed
and the handbrake/low fluid level warning lamp will be illuminated. Power for the warning
lamp is internally connected to a supply from pin C0230-19. Pin C0239-19 is supplied power
from the ignition feed from fuse 27 in the passenger compartment fusebox.