Demons are not a type of ghost. They are non-human spirits. Demons can disguise themselves as friendly spirits, but they are anything but.
They feed off the humans in a household, and can sometimes even possess the weak-minded. Since demons can disguise themselves, it is very difficult to identify when you have one.
There are two major signs of a demon’s presence. If you or anyone else in your household is feeling lethargic or depressed (without a history of depression in the family), this can be a major indication that a demon is absorbing their energy. If someone develops a shocking personality shift, even if it’s only for short bouts of time, this can indicate temporary or long-term possession.
If you believe that you have a demon in your home, do not try to communicate with it, and do not try to remove the demon yourself. Contact a local priest or shaman, who will perform the proper rituals to rid you of this haunting.