I believe shadows are true entities. People who have died and upon their passing did not transition forward, but remained behind. Instead of moving to "the light," they found themselves trapped here due to what could be a variety of reasons. Maybe shadows do not understand they died, or have unfinished business here to do. Perhaps, shadows are just people who are afraid of eternal punishment. Shadows could also be people who are suffering from earthly addictions and need to fulfill them, or people who feel helpless and hopeless, people who are searching for family or friends, or even people who are trapped in trauma that occurred to them and are still living in the year and day that their bodies died. The reasons could be many when one considers what causes spirits to stay here among people in physical bodies.