Residual Haunting
A residual haunt is believed to be activity of reoccurring or traumatic actions from past events that leave an imprint on the environment.
This type is probably the most common type of haunting. Because it's characteristics are similar to the intelligent haunting, people often mistake it for an intelligent/traditional haunting. Like intelligent haunts, some examples of activity are phantom footsteps, sounds, images, and scents. One major difference between this haunting and the intelligent/traditional haunting, is that this type of haunting is not considered to be that of a ghost, and there is no interaction with the living. It happens if you're there or not and there is no awareness to the activity that is happening. Think of it like a movie on a DVD.
It is believed that this activity is the dissipation of stored energy from the site. The theory is the energy is stored or absorbed by the site due to repetitive or traumatic events of the energy expended while performing such actions. Similar to a tape player, the energy is stored in the magnetic field of the environment. Over time the energy builds up and is discharged showing a replay of the event, and then the cycle starts again. Some suggest that atmospheric conditions such as storms may initiate the playback. There is also a quantum physics theory that relates the energy as light particles that are dormant until they are stimulated by an outside variable under the proper conditions. Researchers have observed that the energy tends to diminish over periods of time until eventually it is either exhausted, or the level is so low that it is not experienced again. This however may take many years in some cases.