Once we were staying in a hotel in HongKong. At night when we were all sleeping, the door of the toilet will open by itself. My friend noticed that when she woke up suddenly. The same thing happened the next night. We are sure to avoid that hotel if we visit (HK) again. (Memory collected at the Cheng San Public Library during the "irememberGhost stories" campaign from 27 Sep to 30 Nov 2012)