Certain houses, like certain persons, manage somehow to proclaim at once their character for evil. In the case of the latter, no particular feature need betray them; they may boast an open countenance and an ingenuous smile; and yet a little of their company leaves the unalterable conviction that there is something radically amiss with their being: that they are evil. Willy nilly, they seem to communicate an atmosphere of secret and wicked thoughts which makes those in their immediate neighbourhood shrink from them as from a thing diseased. And, perhaps, with houses the same principle is operative, and it is the aroma of evil deeds committed under a particular roof, long after the actual doers have passed away, that makes the gooseflesh come and the hair rise. Something of the original passion of the evil-doer, and of the horror felt by his victim, enters the heart of the innocent watcher, and he becomes suddenly conscious of tingling nerves, creeping skin, and a chilling of the blood. He is terror-stricken without apparent cause.
Algernon Blackwood  “The Empty House”
We know what happened to those who chanced to meet the Great God Pan, and those who are wise know that all symbols are symbols of something, not of nothing. It was, indeed, an exquisite symbol beneath which men long ago veiled their knowledge of the most awful, most secret forces which lie at the heart of all things; forces before which the souls of men must wither and die and blacken, as their bodies blacken under the electric current. Such forces cannot be named, cannot be spoken, cannot be imagined except under a veil and a symbol, a symbol to the most of us appearing a quaint, poetic fancy, to some a foolish tale. But you and I, at all events, have known something of the terror that may dwell in the secret place of life, manifested under human flesh; that which is without form taking to itself a form.
Arthur Machen  “The Great God Pan“