The Earth Bound Spirit is one that is encountered in investigations at times or via photo's etc. These are "Ghosts" the term used for ones not yet crossed to the Light where they become "Spirits". In general terms these are ones that for whatever reason have not found there way to the Light to the other side of the after life. (Heaven) if you choose that thought. They are stuck on the Earth Plane or Astral Plane. They are in effect very much in their own little World. Not knowing at times they have infact died from the body. Or out of fear that they are not worthy of the Light do not cross over. This too can be many a reason. They remain very much aware of our physical World but lack the ability still to interact with that World. They often wonder in search on someone that can see them. That can help them understand.
This is where ones such as Mediums can and do step in most times, too anyone can cross a "Ghost" if that "Ghost" is willing to hear you and find the Light you can show them. If they are not willing to go or can not let go of the fear of going then Earth Bound they might very well stay.
Why the do not go is many fold, it can be out of a traumatic sudden death that is not processed, or suicide (being thought to be Sin), fear and or con fussion, religious beliefs, guilt, unfinished business, or attachment to family. This is where the need to be made aware the physical body is gone from them and they are not physical in nature.
Too of course there are ones that choose not to go or are meaner in nature and want to stay these one take a great deal of work at times to move on. It is said all can be moved on.
Paranormal Related