Psychosomatic hauntings are simply a figment of a person's imagination. This is the most fragile situation you can run into with respect to hauntings, and at the very least, it is one of the most volitile.
A psychosomatic haunting can simulate any type, or types, of real hauntings. It can also produce visible effects much like a real haunting, except that in this case the disturbances are unknowingly caused by the person being haunted and not by any actual outside force.
Often the paranormal activity produced by these hauntings will continue to manifest after being cleansed. The only way to truly dispel this type of haunting is to build the confidence and faith of the person that is haunted. Since it is thier own mind causing the disturbance, thier own belief that it has ended is the only real way to end the haunting.