Weird spooky occurrence: Lit a relatively small candle (few cm in diameter) and placed it in an iron sconce (candle holder). Walked out of the room, few minutes later & the fire/smoke alarm goes off: the candle's flame is almost reaching the ceiling (several meters high, flame is burning strong like a broken fuel pipe), and it's hot enough to melt the iron sconce...used the fire extinguisher to put out the fire, and literally nothing else was damaged, except for the partially melted iron sconce. That was definitely one of those "That was weird!" moments in my life, with no easily identifiable cause to such a powerful burn. ;-)