Heres a classification of Ghosts.
Ghosts are the sentient remnants of dead people and animals.
Phantoms
Are ghosts which so closely resemble the living that they are often not realized as ghosts until they do something uncanny, like walk through a wall.
1) Phantom Hitchhikers - According to many urban legends, these are ghosts who typically interact with the living in such a way that they ask for a ride, and before arriving at the destination, they mysteriously disappear. Usually occurs on the anniversary of their death.
2) Phantom Travelers - Ghosts that are found along a certain route, usually as a result of a deadly accident . They can be riding horses, or prepared to board a train or plane. Most manifest on the anniversary of their death
Apparitions
Ghosts which clearly such are known as apparitions.
1) Atmospheric - Also known as a residual or replay haunting, these are typically seen in only one location repeating a certain action again and again, usually something attached to a traumatic event.
2) Crisis or Deathbed - These appear to family or friends around the time of death. According to Trent Brandon: "They are very common ghost sightings, but almost never occur more than four days after death."
3) Family - Ghosts which are connected to a particular family, they often foretell death and disaster.
4)Haunted Objects - Instead of haunting a location, a particular object is the anchor for a ghost.
5) Photographic - Ghosts that are not seen until after a photo is taken and examined. These MAY include orbs, mists, (ectoplasm) vortexes, shadows and other unusual light or optical effects.
6)Historical - Typically dressed in period clothing and often appear solid.
7)Recurring - Ghosts that appear on a certain time schedule or anniversary; usually annually.
8) Transportation - they are often associated with the final moments of some tragic accident.
9)Marian - What some believe to be appearances of the Virgin Mary. This could also cover cameos by other saints or religious/spiritual figures.
10)Battlefield - Also known as Floating Battlefields, they resemble an actual reenactment of war, but for some reason, they typically occur above the ground. From several to a hundred feet up, in some cases.
11)Grey Ladies - The ghosts of women who died in sadness over love or betrayal. Can be white, grey or black.
12)Radiant Boys - Legend says that these are the spirits of boys murdered by their mothers. Often appear as glowing bright specters.
13)Mirror - These are the apparitions which are seen in the reflections of water, glass, etc. but do not appear as a direct image.
14) Out of Body - The appearance of a living person who is actually in another location. They are not necessarily ill or dying, and can be either solid or translucent. Some claim to recall their OBE and can give verifiable details about the location they were seen. Probably related to Astral Projection.