These kinds of ghosts may be the most common. These spirits usually appear shortly after their deaths to people close to them. They are aware of their deaths and can interact with the living. They most often bring messages of comfort to their loved ones, to say that they are well and happy, and not to grieve for them. These ghosts appear briefly and usually only once. It is as if they intentionally return with their messages for the express purpose of helping the living cope with their loss.
"This category commonly involves one-time visits to someone with whom the apparition has close emotional ties," says Lauren Forcella at Paranormal Investigations, who calls these ghosts "crisis apparitions." "Though the encounter usually seems to be a type of farewell, sometimes important and useful information is relayed to the 'viewer.' Though dying is the most common crisis, other life-threatening situations can also trigger apparitional visits."
This type of haunting is the most feared by people because it has the greatest ability to affect our physical world. Poltergeists are blamed for unexplained noises, such as wall-banging, rapping, footsteps and even music. They take our possessions and hide them, only to return them later. They turn on faucets, slam doors, turn lights on and off, and flush toilets. They throw things across rooms. They have been known to pull on people's clothing or hair. The malevolent ones even slap and scratch the living. It is because of these sometimes "mean-spirited" manifestations that poltergeists are considered by some investigators to be demonic in nature.
Other investigators, however, believe that poltergeist activity is not caused by ghosts at all, but by certain living people under stress. "During a poltergeist experience," writes Lauren Forcella, "the agent, in an attempt to relieve emotional stress, unknowingly causes the physical disturbances using mental forces. The mental mechanism that allows the poltergeist agent to unconsciously cause these physical disturbances is called psychokinesis."
The skeptics' point of view - if they are willing to admit there is anything to haunting experiences at all - is that they are all in our minds, or are products of our own minds. Ghosts, they say, are psychological phenomena: we see them because we expect to or want to see them.
A grieving widow sees her dead husband because she needs to; she needs the comfort of knowing that he is alright and happy in the next world. Her mind produces the experience to help itself cope with the stress of the loss. Since we know so little about the power and capacity of our own minds, it's possible that they can even produce physical manifestations, such as apparitions and noises - projections that even others may be able to see and hear. But they are not "real" in any sense, say the skeptics, just the conjurings of powerful imaginations.
Are there such things as ghosts? The phenomena of ghosts and hauntings are very real experiences. It is their true cause and nature that is the ongoing mystery.