Sawing into structural components to see if they are load-bearing is a bit like short-circuiting wires in the panel to see if there's current...
That's exactly what the electrician at work did.
He was supposed to install something and needed to cut the power.
So he stuck a screwdriver into a socket to see which fuse it was.
And there I was at the computer, right next to it, writing a long report when everything went black