White Dripping Sculpture of Evil Growing in the Basement

by AM
(Toronto, ON)

I saw this movie probably in the late 70s/early 80s. All I remember is a little boy going down some wooden stairs to the basement where there's this old man, a bunch of people (who I think may have all been possessed or gone to the dark side) and a tall white milky dripping blobby sculpture growing out of a wooden vat that reaches all the way into the ceiling.

It is not "Prince of Darkness"... I saw this one on TV.

Does anyone know what movie this is?