Haunted People. Is There Such A Thing?

This is a strange topic. But, sometimes a "place" just isn't haunted. Because no one is having the experience. Or, maybe when something is "happening" is when a particular person is around. Strange, huh?
There are several things that can be the cause. And, that's only if you believe in these particular causes. One, can be just plain mental illness. The onset of the illness can come anytime in a person's life. That's something not many people are aware of. The person might hear, see, even smell thing's that no one else is noticing. All of a sudden. So, they may really believe their are spirits around them. Two, can be a demon entered the body of the person. Three, the person's psychic abilities. Whether they know it or not. Is coming out. Usually it tends to come out as they age. But, this can be also seen as mental illness. If a person is psychic, and not know it. They believe the place that they are residing at is haunted. But, after a while it's noticeable it "follows" only them wherever they go. And, know body else is having the same experiences.
That's when people go on a ghost hunt they feel relief when someone else is having the same feelings as themselves.
So, what do you do in these cases. I believe a person should seek medical care first. If it's really going to the point that becomes a real true concern. As for demons. Many Catholics and other religions believe that this can truly be very real. And, you should seek help of a priest. Last, someone becoming a psychic? It pretty tricky. There are many sites on the Internet that can connect a person to the right people. They can determine maybe through testing if this is really the case.
But, my very last thought on this topic. Maybe a spirit is "attached" to the person. Again, that's a very hard thing to determine. Then you need some sort of cleansing. And, you need a spiritualist to help you. If you so wish.