Gomer Pyle, U.S.M.C. to Mannix

The Lucy Show's Lucy Carmichael was accidentally drafted into Gomer Pyle, USMC's company on an episode of The Lucy Show.

Here's Lucy's Mary Jane Lewis was originally a character on The Lucy Show (also called The Lucille Ball Show).

Here's Lucy's Lucy Carter and Mannix's Mannix are held hostage in an episode of Here's Lucy.