Earthbound spirits, commonly known as ghosts, are deceased souls who remain attached to the earthly realm after dying. When the body expires, the spirit of a person usually moves into the astral realm (via their astral body) to begin a new existence.
There are instances of spirits that have suddenly died but somehow stay unaware that they are dead. Time is spirit is different from ours and their reality might stay stuck in time for decades. This is difficult for those of us who are living to comprehend.