Types of hauntings
Activity can occur when something traumatic/stressful occurs, such as a murder or even an imprint of a routine event. Like a recording tape, it will play the events over and over again. The entities involved in this residual haunting activity are unaware of their surroundings. This is not an intelligent haunting, there is no interaction between you and the entity.
:Poltergeist German for "Noisy Ghost". It can be an especially activate or mischievous ghost. They can also be caused by extreme emotional turmoil often seen in teenagers.
Shadow People or Shadow Creatures