328 Brake pad wear sensor?

Hi, on my (non ABS) euro 88 328 GTS I found a wire connected to the backside of both front wheel hubs.
It is not connected to the brake pads, so what is it for? A ground? For what?
However, this would be very strange place to locate a ground wire.
Any thoughts?
Thanks.

 

The wire is part of a circuit that is supposed to light the in-dash "brake" warning light if the pads get too low. That requires, though, a pad that has the other part of the circuit, a small stud that is exposed when the brake pad is worn. I don't know of any replacement pad that actually has that piece, although I'm sure I'll be corrected.

 

+1 -- the stock 328 front pads (that might now be unobtanium) have a wire embedded in the friction material that will make contact with the rotor when the friction material gets down to a few mm remaining (creating a ground and illuminating the warning light):

https://www.ferrariparts.co.uk/part/ferrari/135704

Someone probably used an aftermarket set of pads without the embedded wire. (Note in that link that even MC is offering an alternative 328 front brake pad with "No Wear Sensors").

 

I was shopping for front and rear brake pad sets for my 89 recently, and couldn't find ANY pads available anywhere that came with a sensor wire.

 

Okay, thanks! So it is a ground through the dash warning light.