When we moved into our last apartment the previous tenant (a friend of my wife) told us the oven was broken and had never worked all the time he lived there. (As he never cooked this was no real hardship.) We informed the landlord and were promised a new oven the following week. Shortly before the new oven arrived I was struck by a bout of insomnia. At 3 a.m. I walked into the kitchen and found it strangely hot. The oven interior was lit from within. The element burned (as I discovered later at about 400 degrees) brightly. It was clear that at some point someone had messed with the timer knobs and for some years the oven had been coming on for two hours between 3 and 5 a.m.