I'm going to go out on limb here.some believe that our souls

are energy .now if we die . that energy has nothing to keep

it in a physical place the energy moves freely .but when the

energy has a grounded form it my became transparent

or semi solid once more but since it free moving energy

it need other energy of the same type to ground it self

that's why I think most ghost sighting happen in hotels,bars

and places of that sort. If the ghost memories are intact

again this only speculation it my be trying to say he /she is still

here but because the energy required to sustain physical

or semi physical form is to great to maintain for long we

miss out on what is trying to be said

to help with my theory try to research ghost of Gettysburg and

other well know place also try a place called the devils

back bone these are two place were a lot of ghost activity is

reported