Nope. Never.
O.k. I can think of a couple. One ocurred when I was a young car stereo installer in the '80s. I sold a cassette deck to an older gentleman for his old Ford Courier. His truck had a rats nest of wiring where he had added extra lights for his canopy and other crap. I installed the deck, carefully (I thought) checking all of the wiring and making sure the radio was well grounded. The guy picks up his truck and is backing out of his parking place as I watch, turns on his headlights and... the cab of his truck suddenly fills with smoke. The truck lurches to a halt and he stumles out coughing.
Turns out I didn't check the wiring well enough. Somehow I tapped into the headlight circuit. Fried some of his wiring, fried the tape deck. He was cool about it, but I ended up spending A LOT of time fixing everything and ate my commission on the whole deal.
Once, when installing a small amp under the dash of a car I drilled some holes in the firewall to mount it. Stupidly, I didn't check what was on the other side and drilled a hole perfectly through the center of a hard brake line. (what an idiot... )