I inspect houses for a living and one time I came across a breaker that had apparently kept tripping so the owner very tightly wedged a 2x4 between the breaker and the wall to keep it from tripping. Genius.
My house, before the current one, i didn't build, it already existed and I just bought it. Well the shop had a panel, someone knocked out the metal pieces, but didn't put in breakers, when i was doing my inspection of it, i told the owners, who looked at me blankly like they had no idea that was dangerous. Sure would be easy for somebody to stick their fingers in there.