The Haunted House had once been a true haunted house... and it had been proud of that fact... it was no haunted mansion or haunted castle... but it still had its pride of being a resting place of various spooks, ghouls, and beasties... none of that 'Casper the Friendly Ghost' or 'Poor Misunderstood Teenage Sparkly Vampire' or 'Poor Misunderstood Socially Persecuted Werewolf' garbage, true and sincere MONSTERS and GHOSTS.
But... in modern times it had lost all of its inhabitants to ghost busters, monsters hunters, and the like... the monster in human form who owned Pleasure Island had bought the house cheap... then had his shadowy servants move the entire place to his island... where the cheap jackass had filled it with cheap fakes (no offense to the poor humans who ended up slave labor).
But finally, these four... who had slipped in without paying... were not under any binding protection from the 'hands off' agreement the owner of the island had with the house, forcing it to play dress up so humans could get drunk and dive into the base and destructive urges.
It waited until all four had entered, then-
"HEY! The window's stuck!... It won't open!"
"Dangit!"
"Great idea dude."
"Shut up!"
Of course, unlike the movies, the humans knew better than to simply separate for no good reason, strength in numbers, few in real life were truly that stupid. So it was a matter of picking them off one by one, recruiting them to its side, and then the four of them would help them add more guests to the house. A much preferable fate than ending up donkeys or glue. They should really thank the house for what it was about to do. Since they were doomed never to leave this island human anyway.