Specters are usually another name for a ghost, phantom, or apparition. It mainly applies to metaphysical energy beings who only manifest themselves visually with little other effects. Usually something between a harmless ghost and a dangerous Poltergeist. It often describes a shadowy looking entity or one that appears quite menacing. Something whose paranormal bark is far bigger than their supernatural bite. A ghost, spirit, or even a low-level demon with minimal power. An entity with the ability to energize photons within our reality to at least appear to a noticeable extent. Even if only a faint transparent hologram like figure.
Sometimes Specters are caused by metaphysical malfunctions that leave a residual image that may or may not move about. A situation where a deceased person’s soul moves on to the Heavenly afterlife yet they leave behind a lingering ghostly hologram running on a loop. Such an entity has no sapience and eventually runs out of steam before dissipating into nothingness. One sign of such a spectral ghost is the lack of environmental changes such as the air getting colder or energy being drained from the electrical system as seen by flickering lights.
These malfunctions of the soul are caused by heightened emotions upon death. Something not traumatic enough to form a real ghost. Some sub-conscious unfinished business that isn’t quite enough to prevent a spirit from moving on into the light. When the specter moves it indicates that a ghost was close to forming. The movement is caused by the four-dimensional nature of one’s soul. In essence, several 3-D images appearing to create a movie of sorts.