Someone, who at one time, had substance on this earth. They exhibit all the mental attributes that you and I have such as thought, conscience, emotions and emotional needs, morals, calculation, ego, personality and everything that makes up the human psyche. My experiences with ghosts and ghost hunting has served to reinforce this ghost theory and I am grateful. Life is energy. Energy can neither be created nor destroyed.
Science fact is that energy can only change forms.
My suggestion is that ghosts are the what, our life energy. When we die, we are still ourselves. Our life energy still exists, only it cannot reside in a body that no longer functions. Just because we do not understand this immeasurable form of energy does not mean we should deny its existence. It is strictly belief that people move on to some other destination upon death.