[landrovered]

When the brakes get hot it can melt the plastic surrounding the wire, water or bare wires touching metal can cause a short which temporarily causes the light to come on, it dries out or the wire moves and it goes off. Also the brakes might have worn most of the way through the wire and it is not completely broken through yet, same thing can happen. There is a lot of air moving around the brakes, wires can wiggle, there is a lot of vibration as well. Stuff happens to little wires in a hurricane while there is an earthquake and a monsoon.