Major MAJOR GOOF!!!
Or perhaps it was just bad direction. At the end of the Hymn For a Sunday Night musical number, they dissolve from the McAfee family in white robes to Mr. McAfee coming out of a trance which we are led to believe he was in during the entire duration of his imagined musical number. It's really hilarious because all the other actors in the shot look at him with concern as if he was standing up unconcious during the duration entire number.
There is no "off" position on the genius switch.