Get a mechanic to hook up a buzzer on the light circuit
then make the lights come on,,, them move the wiring around
under the dash, particularly the brake light switch.
When the buzzer stops narrow the area down to an exact area
and use appropriate insulation to shield offending wire.
And fix the culprit.
Sounds like a switch wire is being earthed.
P.S. There could even be a clicking sound as well
if it has a relay...
Cheers.
Mars Mission.
