The Alfred Hitchcock Hour - Season 2 Episode 13 : The Magic Shop 1965

Tony Grainger is a young boy who gets fifteen dollars for his birthday. He asks his father Steven to take him to an out-of-the-way magic shop so that he can spend it. Mr. Dulong, the mysterious owner of the shop, takes an interest in the boy and agrees to teach him everything he knows about magic. Despite his father's protests Tony is invited to step into a cabinet by Mr. Dulong. Ignoring his father, Tony steps inside and promptly disappears. When Mr. Dulong, himself, disappears Steven is shocked. The next day Tony comes out of the cabinet and acts like nothing happened. Eventually the Grainger's realize that there son has become a master of black magic and that they are helpless in the face of his dark power.