Comes from the incomparable Shirley Jackson:
"No live organism can continue for long to exist sanely under conditions of absolute reality; even larks and katydids are supposed, by some, to dream. Hill House, not sane, stood by itself against its hills, holding darkness within; it had stood for eighty years and might stand for eighty more. Within, walls continued upright, bricks met neatly, floors were firm, and doors were sensibly shut; silence lay steadily against the wood and stone of Hill House, and whatever walked there, walked alone."
If you've never read The Haunting of Hill House, you should.