This isn't an instance of me frying some hardware, but an amusing instance still.
Back about 12-14 years ago we were working on a new product that supported two new cameras from Dalsa, one a high speed 2k linescan camera, and the other a high speed 2kx2k areascan camera. Both cameras were in identical packaging with identical connectors. However, the linescan camera operated on 24v and the areascan camera only operated on 12v. Needless to say, it was entirely possible to connect the 24v power supply to the 12v camera. Our lead engineer was constantly lecturing everyone about the risk, and to always be sure what camera and power supply they were using (the power supplies were identical in appearance as well). About a month into the project, the lead engineer was the one to plug the 24v power supply into the 12v camera. And of course, the areascan camera was the more expensive of the two as well, $20k at the time vs I think $7k for the linescan.