Is that what you think they’re getting arrested for?
They almost always didn’t do it just to scare people, there was always a motive for monetary/social gain. Most could be argued as being fraud, insurance scams, etc.
I believe in many cases where the “villian” pretends to be a ghost/monster/creature that is haunting the grounds of a location, they do so in order to devalue the property or scare off other investors/buyers. The next step of the plan is then to come in and purchase the property at a lower price than what would be fair market value.
IANAL, however I believe this would be fraud. They are misrepresenting the situation for their personal gain.
Could also violate some stated Anti-Ku-Klux-Klan laws that make it illegal to wear masks to frighten people.
Typically the villains were stealing gems, or pillaging treasure or stuff. The ghosty part was just to try to keep people away. Albeit there was one movie where the entire village was in on it and it was a bid to drive up tourism.