He provided narration for several segments on the Disney anthology television series between 1954 and 1965. He was the voice of the Mouse in Goliath II in 1960 and Professor Ludwig Von Drake, who first appeared on that series when it moved to NBC and changed its name to Walt Disney's Wonderful World of Color in 1961. In 1966, he dubbed the voice of Eddie (portrayed by the late Dick Wessel) in The Ugly Dachshund during post-production.
In 1967, he provided the voice of the Auctioneer and the Narrator in Disneyland's Pirates of the Caribbean, and Adventure Thru Inner Space attractions, respectively. Clips of his voice from the Pirates of the Caribbean attraction can be heard in the 2007 film Pirates of the Caribbean: At World's End. In 1969, he provided the voice for what may be his most memorable role, the Ghost Host in Disneyland's Haunted Mansion. Later audio of his laughter as the Ghost Host, would be used for the Hatbox Ghost, when the character returned to the attraction in 2015.
Frees also makes an appearance in The Shaggy Dog, as Dr. J.W. Galvin, a psychiatrist.