When imaginary ideas get attached to the ego, they become ghosts. There are two main types: ghosts of opportunity (o-ghosts) and ghosts of threat (t-ghosts).
Ghosts grab and feed on your attentional energy in a bid to grow, to be complete and to be realized. They grab it by making illusory promises; but of course, their true goal is simply survival, not fulfilment of promises.
So with the acquired attentional energy, they then recruit mental and physical systems to generate cravings, clingings, aversions and urges and impulses, which in turn generate scheming, worrying, fantasizing, restraining, executing… and a whole cocktail of emotions.
People who are deeply possessed by ghosts have a distracted and haunted look. And generally, only when the ghosts are realised, is the ego released of them. This release causes relief – a sense of pleasure and joy.