Gaston Leroux 
The Phantom of the Opera By Gaston Leroux 

In which the author of tis singular work informs the reader how he acquired the certainty that the opera ghost really existed The Opera ghost really existed. He was not, as was long believed, a creature of the imagination of the artists, the superstition of the managers, or a product of the absurd and impressionable brains of the young ladies of the ballet, their mothers, the box-keepers, the cloak-room attendants or the concierge. Yes, he existed in flesh and blood, although he assumed the complete appearance of a real phantom; that is to say, of a spectral shade.