@chuteandladder Hi! I don't have the Paranormal Stuff yet but I'm betting you can find that haunted house in your library. I remember when I got Tiny Living, there was an option to set up a tiny house right after I opened the game. I decided to wait and later found the pre-made tiny house in the library. It might be easiest to open library and then click the Maxis option on the left side. This will filter out everything so that only the Maxis pre-made lots / households are displayed so you can more easily find the haunted house.
I also think you could probably set any house / lot as Haunted House from Build Mode. To test that, choose a lot from world view and click the Build button in the lower right. Then click the House icon in the upper left corner. Click on that drop down menu under Lot Type and look for the Haunted House option. Let us know if that works!