The only sensible reaction to an apparent demonstration of a ghost is, not than to say "hey, that disproves science!", but to try to reproduce the phenomenon and find out something about it. You might find, for example, that a natural phenomenon like a subsonic frequency might trigger a physical reaction in the brain. The expression of this could be influenced by culturally acquired mental forms, thus explaining why ghosts change from society to society and from one age to another. Of course, it won't explain photographs, but that's a matter for a different study.

It's worth knowing what a ghost is. After all, if you're going to spend the next 400 years flitting across a deserted churchyard, you don't want to be known as The Man In Purple Lycra Shorts, do you? As my Granny always said, make sure you're wearing fresh underwear, in case you have an accident and have to go to hospital.