A haunted house is a building
that is very dark and has a lot of scary things in it. They usually have
models of dead people jump out at you. Sometimes there is a point where
a lot of steam suddenly bursts out in front of you. 
They are very fun and scare you out of your wits. Most likely you are put
in a little cart where you are driven around on a track and have little
things pop out at you, or driven in ghostly scenes, or just about to be
crashed into a wall but suddenly turned away at the last moment. They are
very fun because you get scared out or your wits. 
http://perso.libertysurf.co.uk/markwd56/CumnorPlace.jpg
So haunted houses are lot of fun because there is a lot of excitement and frightening images that are around and dead models are always popping out at you. Since they are scary they make you want to go on them again and again.