Martin Ragaway wrote this story, and a few others for the show, who did a ton of material for Red Skelton and Dean Martin. The only difference here, a lot more fantasy than comedy, but it works.
It's all about a young and handsome dentist, played by character actor Don Reid. He needs a babysitter, but theres a communication breakdown -- and patient Marcia believes he wants a date? A teen LOVE, AMERICAN STYLE situation.
With a little re-working, this could have been a story about two adults in a romantic mess.
There's a fantasy slash soap opera sequence, a first for the series, and you know the REAL truth is going to come out. Bummer day for Marcia.
Good side story with the guys working on a cool go-cart --which finally, finally starts up. In a way, the episode separates the guys from the girls; romance versus high speed adventure, and watch Alice almost get run down by the go-cart.
By the way, if Don Reid looks familiar, he was a popular actor in the 70s and 80s, later appearing in soap operas.
I'd give it a 9 for sentimental value and, especially, all of us forever Marcia fans. From SEASON 4 remastered color ABC/Paramount dvd box set.