Ventriloquist Jerry Morgan has failed with another love affair. The reason: when the relationship reaches the point when it is time to discuss marriage, his two dolls become mean and jealous. Morgan's dollmaker Papinek is a member of a spy ring who has stolen the secret plans for the top-secret Lafayette airplane. Since Morgan is leaving for Zurich the same night, he decides to hide the secret plan in the heads of the dolls.
Unfortunately the movie Knock on Wood is not yet available on HBO Max.
| Directing | Melvin Frank | Director |
| Writing | Melvin Frank | Writer |
| Writing | Norman Panama | Writer |
| Directing | Norman Panama | Director |
| Costume & Make-Up | Edith Head | Costume Design |
| Production | Norman Panama | Producer |
| Production | Melvin Frank | Producer |
| Art | Hal Pereira | Art Direction |
| Art | Henry Bumstead | Art Direction |
| Camera | Daniel L. Fapp | Director of Photography |
| Costume & Make-Up | Wally Westmore | Makeup & Hair |
| Art | Ray Moyer | Set Decoration |
| Editing | Alma Macrorie | Editor |
| Art | Sam Comer | Set Decoration |
| Sound | Victor Young | Original Music Composer |
