Once, and it was when I too was a lighting rigger / grip after HS.
The company had rented a rack of floods. Unknown to us, someone had re-lamped them way over the max wattage.
And when they were faded in -- for the first time -- during dress rehearsal, the fixtures started to smoke and the bases melted, setting fire to the gels. :eek3:

I don't know why the circuit breaker didn't trip, but I lunged for the extinguisher at the first lick of fire.
It blanketed the stage below in foam, and a couple actors took an impromptu shower.
But in the end, the show went on. h:

I did have one in the old GTI on account of the nitrous, but thankfully I never needed it.

IMO, you need at least two for a decent sized apartment.
One for kitchen disasters and one to buy some time if you're trapped in the bedroom and a fire breaks out.