Many pictures once hailed as classics have crumbled in the light of modern analysis. In the relative youth of photography, long exposure times left many opportunities for deliberate or inadvertent interlopers to themselves as ghostly presences in a scene. Techniques such as double exposure were also a gift to charlatans or cultural tricksters. Today of course, the problem is magnified tenfold. Not only are cameras ubiquitous - carried by almost everyone in their pocket - but are now digital. This offers new opportunities for mistakes and hoaxers alike. Motes of dust near to the camera lens and caught in the strobing light of a flash are advanced as an explanation for the photographs of so-called 'orbs', which others take to be representations of the souls of the dead. For more concerted fakers, tools such as Photoshop have created many ways for the technologically literate to create beautifully realised fakes.
But yet: just because ghost photographs can and have been fakes does not necessarily mean that all ghost photographs are fakes. While the emotional appeal to the sceptically-minded is powerful, it is also a basic logical fallacy.