... How could I possibly make my actor, which is supposed to be a ghost wandering around a tavern and praying at a daedric shrine at night... appear only at night? Thanks!

Thanks.

I suspect you probably want to have a look at packages

http://www.creationkit.com/Packages

Thanks! So I should use the Interrupt Behavior Override Packages command, right?

...as for the actor only appearing at night I still don't know how to do it.

I decided the actor would be in a cage instead of being bound, too much hassle for nothing.

But I still don't know how to make my actor appear at night. I don't want him to walk away from the place, but to completely disappear... any clues?

There's a package tab that lets you specify the hours when the package is active. You can make one package active during night time hours, and then give it a ending fragment that moves the ghost to a warehouse cell somewhere. And the same in the warehouse to move them back

Alright, I'll see if that works.