Are All Ghosts Really Ghosts??

Kevin Dooley - Creative Commons

I came across a passage in a book recently that totally floored me! I had never even considered this thought before and was naturally wondering why it had never crossed my mind. Are ghosts only spirits of those who have passed away or are they also living astral bodies that have traveled to another location? Here is a couple of examples:

"'I [a professor] resolved to try whether I could project my astral body to the presence of A [his fiancee]. I did not at all know what the process was, but I opened my window, which looked toward A's house, and sat down in a chair and tried as hard as I could to wish myself into the presence of A. There was no light in my room. I sat in that state of wishing for about 10 minutes. Nothing abnormal in the way of feelings happened to me.' The professor visited his fiancee the next day. She immediately told him that she had seen his apparition at 10 the previous evening while eating dinner. She had looked up from her meal to see the gentleman staring at her through the dining room door."

If we can project our astral bodies to other locations what then is the difference of that and ghosts? When spirits of the dead appear and attach to earthly locations there is some kind of equivalent tie to astral travel. In some ways I find this close to remote viewing but with a twist. Now, it would be interesting to see if any travelers have been able to sense ghosts astrally as well as physically. I have not found a reference to this yet.