Placement of kill switch and other quirks
Probably similar timeframe - VAX 11/780s in late 1970s. Kill switch next to a phone on the wall... Engineer makes call on phone, leans against wall,.... lights out!
Same installation. Telecomms 'electricians' removing a cabinet. Not sure if power is off. Large screwdriver between active and earth shows, momentarily, that power WAS on, lights out once again.
Some air-conditioning fun from same location if On-Call is interested in that sort of thing.