When I was about 14 and living in Ottawa, Canada there was a story circulating about a babysitter who, after putting the children to bed, heard the washing machine or dryer turn on for a brief period and then turn off again.
Now, the laundry room was situated on the ground floor of this split-level home. At first she thought nothing of it, until it turned on again and then off again. She thought perhaps it was just a strange washing cycle and the parents had forgotten to turn it off.
She proceeded down the stairs to investigate when suddenly the washer/dryer turned on again. She paused on the stairs until it turned off. She was now overcome with fear and decided to go wake the children upstairs, afterwards proceeding out the back patio door over to the neighbors’ house.
The neighbors thought she was over-reacting but they called the police anyway. The police arrived to investigate and discovered a man standing in the laundry room holding a knife. Apparently he was waiting for the babysitter to investigate the noises.