Can anyone ID this movie?

I would like the name of a movie I saw as a child. I don't know the name of it. All I can remember about the film is that it had a married couple with a small child that moved into an old farm house. The husband filmed a commercial in front of his home for his job. The commercial actress was singing about a product called 'Zapples'.I can still remember the jingle. When he played back the film his wife saw the devil's eyes in the background. Then their little boy was possessed by the devil in the form of a bullfrog he was chasing. I know this whole thing sounds silly but all this was in the film. The movie was made in the late 60's/early 70's. It's been years since I saw this movie and never came across it again after all this time. Does it sound familiar to anyone? Does anyone know the name of this film?