Scooby-Doo, Where Are You!

A Night of Fright is No Delight (1x16)

Air date: Jan 10, 1970

Scooby-Doo inherits a mansion because he saved the Colonel from drowning years ago. He and some other heirs will each get a fortune but there's a warning that the house is haunted. The warning appears justified when someone (or something) comes to frighten the heirs away.