Flashing warnig light

I have a p reg 300 tdi auto. The handbrake light occasional flashes whilst driving. Inconsistently. Fluid level ok, brake pads ok. Ny ideas what causes it flash/flicker. does it for short time then may be nt for couple of weeks. running out of what to check and at the moment i am just trying to ignor it i the vain hope it will go away.

Dogey switch on the handbrake? Wire rubbed through letting it touching the body somewhere?

Take the brake reservoir cap off and check that the float is moving freely up and down and isn't sticking.

Thanks i was hoping it would be something like that. another efternoon crawling around under the car then.