I was playing my electric unplugged last night, just farting around as usual - when, all of a sudden, the black knob on the bridge pickup's tone control just rattled and fell off! It's the weirdest thing that's ever happened - I hardly ever used it.

As far as I can tell, the control still works alright, but of course it's now just a little metal pin sticking out of the guitar, and it looks really dodgy... I tried putting the knob cover back on, but it wouldn't stay. I don't know how I could have broken it - like I said, I rarely used it and I never tampered with it at all. In fact, the only time I've ever maintainted/modified this guitar is when I changed my strings yesterday - but that can't have affected the bridge pickup tone knob, could it?

My question is: does anyone know how I might put the knob back on/get a replacement? Also, does anyone know why this might have happened? I just hope that my relatively new guitar isn't falling apart at the seams :(

Thanks everyone.