I was building a new office area in a warehouse for an Ace Hardware distribution center. Had to install four 2x2 flourescent drop in lights.
We were working at night (to stay out of the way of daily operations there).
Hooked the first one up to the existing wiring. Turned it on. "Damn, Thats awful bright!!!" - after 60 seconds " that looks like smoke under the lense" - 120 seconds "OH CHIT!!!".
turn it off, must be something wrong with the light.
Pull another one out of the box, wire it up.
Flip the switch.
Same thing happens.
Something must be wrong.
Chase the wiring back to the panel.
It's hooked up to some weird voltage - I think it was 273 or something odd like that. What an eye opener!

I can deal with 110 or 220, but getting into that odd stuff - in the future I'll leave it to someone else.