Scooby-Doo! Meets the Boo Brothers (1987)

After the death of Shaggy's Uncle Beaureguard, he, Scooby, and Scrappy arrive at his uncle's plantation to collect the inheritance. But as soon as they arrive, they find it is haunted by the ghost of a Confederate soldier. With this spook on their tails while they search for Shaggy's inheritance, they hired to help of the Boo Brothers, a trio of ghost-exterminators to help catch this nasty ghoul.