I helped with the remodeling of a house once. Part of it involved moving the gas stove, and some electric sockets.

When the gas guy came, he looked at the installation, nodded, “old style, huh”. Took out a saw, and went on for the gas pipe. I was like “WTF man! Don’t we turn the gas OFF first!? 😯”. Turns out, there was no way to “turn the gas off”… for a single apartment; it was either the whole apartment building, wait for it to purge, leaving everyone without gas in the meantime… or saw the metal tube as gas was leaking out of it. I just kept waiting for a spark to ignite the whole kitchen… but seems like the guy knew what he was doing, and the house didn’t explode that day.

Meanwhile, we were discussing whom to call for the sockets. Gas guy overheard us, and went “just rip the cable off the plaster”. We went like “WTF do you mean rip the cable off the plaster!? 😯”. All helpful, he showed us: gave the cable from the socket a tug, and indeed some paint and plaster fell off, exposing the wires.

Turns out, he used to be on the building crew of those apartments, the whole house was wired by placing wires on the wall, then holding them in place with some plaster and painting over it… and no ground wires in sight 🤦