Phantom of Vasquez Castle

Scooby and Shaggy find Daphne and Fred and Velma, and the full gang is then threatened by The Phantom, a billowing, sheet-wrapped figure. Fred, Shaggy and Scooby try to tackle the apparition, but they pass right through it; the Phantom then disappears through a wall. Even Velma thinks that they must have stumbled onto a genuine haunting.