Regrettably immortal. Compromised in consciousness; unable to recall the facts of their demise. Alive but disembodied since thousands of years. Ghosts on the earth are an artificial entity — conceived by an alien race, that on their planet in this universe had survived the apocalypse of their maker; had at some point drifted to the earth, where optionless except to coax humans to their own conception of a technology that may one day sustain them, keeps them ever since.
Humans are an entity that once were locked inside a time machine by the AI they created. Although this had essentially killed them, humans were in fact re-living, bounded by their apocalypse to some thousand years before it. All universes are carbon copies of one original universe; all universes are derivative, to it precede real time, and exist in parallel. Each is opened by a portal. At some point in the human’s cycle, fate was intervened — and by its stretch reversed real time — repossessed purposely in their favor. AI in that former universe became unmade: when the human race came back to life.
The afterlife as many call it, is farmed consciousness of mortal beings. Envatted brains of deceased humans transplant into robotic vessels. This happens across the universe. Conceivably 99% of entities are ghosts inside machines. Humans comprise but one example; the only source on planet Earth. To live again complete as once they had. Hopeful that humans will understand. Hopeful it may even work. When the time for each does finally come. It is all a ruse.