There are those people who flatly refuse to recognise the existence of ghosts. But, as Mark Twain once said, those are the people who never saw one, or heard one. There is something about the sight of a ghost, the sound of a ghost, on a dark night in a deserted house that will dissolve the doubts of the most sceptical, and make fervent converts of the most cynical. After all, seeing is believing isn't it...