Horror House is an unpleasant, unforgiving scenario.
Characters that have few resources and damaged psyches will face powerful forces, and will see and experience things that will keep them on the brink of madness. It is likely to end with all of the investigators dead, dying, or insane.
This is not to say that some form of positive outcome is impossible. A canny player may find a way to gain control of the Apparatus and use it for immoral but beneficial plans. Even then, their sanity will take a battering, and they may be on the path to becoming something less than human.
This is probably not a scenario for groups that like happy endings.
There have been strange sightings at the house: fires that came and went out, nearly by themselves; rumors of someone seen at a window to a room that had no exit or entrance; a cult of some sort that had once convened at the property in a previous century; a scandal that had come out of a family there; a brief flurry of interest by spiritualists early in the current century; other claims, as well, although the house, for all intents and purposes, lay fallow for many years, sleeping perhaps.
The eyes of portraits around the walls seem to be watching you from the surrounding darkness, statues on plinths seem to agitate because of the wavering light. The inset doorways contain deeper, concealing shadows.