About 20 years ago I worked for an American company in London, and we were prone to getting equipment sent to us from the US. We received a PC from them one day and as IT manager I was tasked with testing the software setup as it was specially configured. So I plugged it in and as you’ve probably guessed by now, yes, it went bang. So I had a look at the PSU and noticed it was set to 120V (this was obviously in the days before switching power supplies could work at any voltage).
So I called the guy who sent it and asked him “before you sent the PC, and after you set it up, what did you do?” And he replied “umm.. I put it in the box” so I asked “...and before you put it in the box?”
“No, just turned it off and put it in the box” he replied. So I then asked “let me ask you a totally different question: when you plug things in, do you generally check the voltage label?”. His said he didn’t. So I replied “well guess what? Neither do I!”.
And then he twigged. “Ah” he said, as he realised what happened.
I’m still friends with him.