I started thinking about this question when I saw an answer to another question about whether Muggles can see ghosts. The answer says that they can, but typically (ghosts) do not reveal themselves; partly because they want to be left alone, but also partly because they fear "punishment" by the Ministry.
My question is, what "punishment" could you give a ghost, or, more accurately, how do you make the ghost want to suffer the punishment rather than whatever else you could do to it? For example, we humans go to jail or do community service because if we don't, the other things the [insert location here] government could do to us would hurt more.
As an example, the answer I referenced says the Ministry made Moaning Myrtle go back to her bathroom, but what I am asking is what could it do to her that would make going back to her bathroom preferable? Ghosts are already dead, so you can't kill them again (or can you?), and they are incorporeal, though probably not completely intangible.
We know from Chamber of Secrets, the book, that ghosts can taste and presumably feel, though barely, as a ghost at Nearly Headless Nick's Deathday Party (which is sadly not in the movie) has to float his head through some type of rotten, spicy food to taste any flavor at all.
However, this doesn't seem to be able to extend very far. Yes, the ghost feels things, so one could perhaps put the ghost in an electric torture chamber or something similar if he/she does not comply, but would they really want to do that for every Peeves-like manchild poltergeist? Is there perhaps a Ghostbuster-style ghost container, able to vacuum up ghosts and put them in solitary confinement, or a Danny Phantom-like "ghost world" (probably separate from the Veil) where they could store unruly ghosts?
One thing I know could make a ghost hurt would be to isolate the ghost from other people/ghosts. Humans are social creatures, and I assume ghosts are the same way, even considering how they are not completely human. However, again, this could only go so far, and some humans and ghosts would love nothing more than to be left alone, so exile would be like a reward for killing innocent humans and causing too much ruckus, rather than a punishment.