I just looked at that page, it's weird how some ghosts interact with people and some don't. Like some aren't aware they're dead and others have become aware. I think seeing a ghost would be interesting, but if he looked back at me and smiled or looked at me malevolently. Well, as Fred Sanford would say, I'd have a big one lol.
Personally I think it's people who are very attached to this life and need more time to let go. It fits with battlefields being haunted. Of course living out half conscious memories for eternity would be my idea of hell, so there's that theory too.
Not if those memories involved a little something with a hot girlfriend. haha
I think the battlefields would more likely be time related or evil entities attracted to suffering. There was one story on tv, Unsolved Mysteries I think, where a guard at Bullrun or somewhere saw a big fellow with green eyes. The bible and Jewish lore have a name for these things, the undead
The record of the Saints, in this biography and that, over centuries and centuries, is of battle with the demonic. They didn't cower. They understood the evil, and the folly of the demonic. They prayed and spoke as Saints the Holy Name. They were beaten, injured, assaulted, etc. by spirits.
It's the superstitious moderns who fear the demons, in whatever form, whether visible or not, because they don't know what to do. They are not Saints, and may even REFUSE to confess God and His Church. 500 years of Protestantism, Revolution and then socialism had a way of doing that to the human race.
But the idea of ghosts and demons, of horrible odors and violent noises, even physical assaults by unseen assailants, are the very stuff of exorcisms, and again the lives of the Saints to whom the demons particularly were sent to make miserable, if it were possible.