In really old times, people whispered about the wickedness of thieves and sinning, and one popular tale/rumour was about the Hand of Glory.
It goes that a master thief carried a dead man's withered hand into the house he intends to burgle, and then lights the fingers on fire. If a finger catches fire, it means somebody is sleeping inside the house--if it doesn't, then it means they're awake. (Or there aren't enough people in the house as there are fingers, which is important and plays into how the thief is often caught at the end, by people in the house hiding or pretending to be asleep.)
Once the fingers were lit, the sleeping people were charmed, and wouldn't wake up until the flames were extinguished, which could only be done by dipping the hand into fresh milk.
A common variation on the tale is that the hand must be taken from the hand of an unborn baby. Preferably done in a graveyard, at the stroke of midnight, and without making any noise. These Hands of Glory were the best, and when lit on fire, could burn forever without being consumed, and also casting a "devil's light", which would light up the darkness, but only for the thief holding it.