Handbrake warning light?

[DLT]

Hello, I have a bit of a puzzle while fitting fog lights I discovered a loose wire behind the fuse box, with a connector that would appear to fit on the back of the fuse box, it's a thin, poss .5mm yellow wire.
I have traced it back to the handbrake warning light.
As far as I know everything works, anyone know what it does?

[kevtherev]

My Haynes lists bl/br and blk to the warning lamp
I have found,
Oil pressure monitor unit has a yellow wire from it to the plate

[marlinowner]

Could it be for ABS which if fitted would use the brake warning light to indicate a fault?

[DLT]

Should say I traced it back to the fitting that holds the handbrake warning light.
There is an empty space above the light, do any versions use that for something?

[marlinowner]

Checked my handbook and yes ABS warning light (if fitted) is above handbrake warning light.
So I rest my case.