Well, it comes down to knowing the haunt theme...is it a victorian house/cemetery? Post apocalyptic? Etc. Think about characters you like, say, the cannibalistic butcher type, or lost ghost, or werewolf, or so on. what they'd fixate on. Match the two and go from there.
Sorry I could respond yesterday, but if not too late.
Open with YOU, cause that is who they are "hiring" and needs to get along with the other actors.
Then, go for scaring laugh, soft voice "welcome back", "nice to see you again", vacant stare, etc....enough for them to get ideas of how to use you.
If turned down, try again, next year after visiting their show and taking notes.