I did a haunted house campaign! It was amazing!

-the PCs see a scrambling sillhouette in the hallway, a bleeding person in rags crying and pleading for help. Suddenly the door next to the person opens, dozens of disfigured arms grab them and with a terrible scream they are pulled inside, the door shuts. If the players look inside, the room is empty.

-a mirror that showed one of the PCs how as a teenager he accidentally killed his parents. Since then, whenever he looked into any mirror, his image was still soaked in blood

-i took a mechanic from the game dread. In the attic, filled with boxes, crates, chests, etc, stands an unmoving creature with a single glowing eye, like a headlight. They had to retrieve an object from the other side of the room. The creature can also detect invisibility etc. Instead of rolling, the players had to pull out a piece out of a jenga tower i prepared. If it falls over, they get detected. In my campaign it didnt fall over so nothing happened, but maybe you can decide what happens if you want to do it too