When a ghost can be seen, it may have a slight glow. Other times when the ghost is more visible it may just have a hazy fog surrounding it so it has no defined edges. They usually also have no feet.
They don't usually have any specific prey, but they do haunt a location or object. Anyone that comes in contact with that location or object is subject to being disturbed by the ghost.
Haunted houses, graveyards, hotels with haunted histories, ships.
Can pass through animate objects such as walls, speed, invisibility, can glow or allow themselves to be seen, can fly, can possess others.
Holy relics, salt, iron.