accidental home physics lesson

Background: while I was in Spain, Nibs had the downstairs bathroom renovated. It now has a tile floor & granite counter to replace wooden ones that the Wendling damaged with various fluids. As part of the renovation, though, we had the mirror taken out. I had to hang up a new one. This bathroom has halogen lamps.

As I'm driving the nails into the wall a couple of feet below the lights, I notice the lights getting stepwise brighter with each blow of the hammer until pop! One of them goes out. I finished the job using the CFL in the hall.

The shock & vibration could have progressively shorted out parts of the coiled filament, and then what, the current exceeded a threshold and melted it? Faskinating.

Oh yeah: the mirror is level because that's how I roll. The light fixture, however, is not and can't easily be made so.