From the Chaosium website:
What is a Haunted House?
Is it a decaying mansion brimming with spires, turrets, and intricate grillwork? An abode of great age with its rotting façade and long-lost, eldritch secrets hidden inside, beneath decades of cobwebs and dust? Does it require spine-chilling drafts and creaking wood that causes stalwart investigators to calm their breathing in nervous anxiety? Or perhaps it is a house hand-built by skilled and discreet craftsmen who don’t mind an eccentric owner's request for a secret passageway or hidden room?
The ideal haunted house seems to issue from the 18th and 19th centuries. Nothing adds to a supernatural mystery than an old abandoned house, whether standing on some lonely country back road or in the middle of the big city. Where once a stately manor stood on a rural estate may now be rotting amidst a sprawling suburb.
Every small town has such an old abandoned house, inspiring local folklore with its spooky, mysterious past and its supposed horrors still lurking inside. Elderly neighbors whisper hushed rumors about previous owners, and what horrors occurred. Youngsters dare each other to enter; teenagers use them for reckless (or romantic) adventures; unknowing and long-lost relatives inherit them; and sinister persons (or things) use them as headquarters for nefarious plans.
Keepers of Unknown Lore are welcome to tweak the designs presented here, adding more secret doors and passages, and strange landscaping to whatever neighborhood they wish to place their own haunted house. Does your scenario need an organ loft where mysterious music flows forth at midnight? A Victorian-era tower turret is perfect. A hidden basement room where once Revolutionaries, Criminals, or Cults secretly met? A decaying Colonial cellar is just the place.
So go on, thumb through this collection and find the house of your nightmares!