There is no theory in any life science that makes a prediction that ghosts exist.
Ghosts have no properties that can be described.
There has never been a reproducible ghost event. This makes it unlikely that the perceived phenomenon was a real one.
The logic that most people use to arrive at a conclusion of “ghost” is faulty. It’s usually “Something inexplicable happened, what else could it be?” A ghost is an unknown. By no logic can a set of unknown properties be considered consistent with your experience. Any other unknown – leprechauns, sorcery, Bigfoot – is an equally valid match.