There are alot of dumb theories in the world.
Vampires are one.
Believing that a dead human being from whom the blood has been removed in a funeral chapel and embalming fluid injected in its place, whose nervous system has completely collapsed and whose tissues have turned to something akin to jelly can somehow return to a form of consciousness and get out of a sealed casket covered with hundreds of pounds of earth and walk around to prey on the blood of the living is ludicrous beyond comprehension.
What would be the source of all that energy? Spirit, you say. I don't see that force at work anywhere else.
There have been movies about ancient mummys coming to life to prey on and attack the living. What nonsense! Embalmers removed the brain and organs like the heart, lungs, liver, etc. Then, they treated the remaining tissues with salts that turned them into something approximating leather. A log would have just as much chance of conscious mobility!
As to the idea that an ethereal soul somehow manages to go on consciously without a brain or nervouse system in which to function, no eye with which to process the parts of the electromagnetic spectrum involved in sight, etc., I'm skeptical. Yeah, I'm well aware of the anecdotes, and they can be very persuasive sometimes. But, I'm also very much aware of how credulous we humans can be and how deceptive and mistaken our minds can be, especially in times of great stress and emotional upheaval. Seeing isn't always believing, as far as I can determine.
I started being skeptical a long time ago, and I'm getting even more so every passing day.