1) the person is schizophrenic and is seeing delusions.
2) sometimes it isn't the person who sees the ghost that is 'gifted' it is just that the ghost is strong enough to be seen by anyone. My husband had a ghost in the house he grew up in. Everyone in the family saw it and guests to the house saw him as well. He never spoke, was never threatening, he was just there sometimes when you went into a room.
3) some people are just really sensitive to things that are paranormal. No one really knows why this is for sure. Some speculate that it is genetic. For example, I don't see dead people but I have a very strong sense of evil. I've been places or been around certain people that made me feel extremely uncomfortable only to find out later that something horrible happened there or that the person had something very dark that they were hiding. My father has the same ability. I don't think of it as paranormal as much as just really good instincts.
Truth is no one knows why some people have paranormal abilities and the rest of us don't. And keep in mind that not all people who claim to see the dead really can. Some people are just really good con artists and are experts at what is called 'cold reading.' It's pretty easy to manipulate people or predict what they are thinking when you know how to read body language.
i see them, sometimes clearly like a face and body. oftentimes it is just their outline. I just attract them somehow but have worked hard to have a stronger presence so they do not try to attack and feed off my energies like has happened a few times before
Sounds like schizoid / paranoid visions to me. Not that there's anything wrong with such things -- I think ultimately even the most bizarre and unsettling hallucinations may ultimately serve some instructive or enlightening purpose.