Ghosts are a type of anomaly that wander the world without a body. A ghost is attached to the earth due to its desires. They have one of two choices; let go of their earthly attachments, or become a demon.
The ghost's "body" is a projection of the soul, and the individual can chose to live as a floating soul if they please instead. The ghostly body is incorporeal, translucent and tinted the color of their soul. Their soul survives after their physical bodies die. Their eyes contain no color or pupil.
A ghost will often roam in their place of death, as well as places they remember during life. Also, a ghost can attach to any person(s) who caused their death and haunt them.
Ghosts interact with humans in an indirect fashion. Rather than touch or speech, they can influence the mood and temperature. They can also cause visual hallucinations in short bursts. Ghosts can possess humans (and corporeal anomalies outside other ghosts) and animals.
While they cannot communicate with full sentences, short words and phrases can reach the physical realm. Spirit boxes and other sorts of mechanisms for communicating with the dead can function if the ghost is willing to cooperate. Anomalies can interact with ghosts, since they have a connection to the spiritual.