What's this switch???

[jimmy2007]

Hi everyone, I noticed this thing that looks like a switch with a long wire to me, tucked behind another wire.
Nothing happens to the dash when i click it.
It's not plugged into anything at the moment, I don't know if it ever was.
It comes from the bottom of the radiator and the switch is loose next to the locking mechanism.
What is it?
On I wild guess I thought of a boot open indicator for other models.
Mine is a B5 1998 1.8T (AEB engine)

Thanks.