Maybe the name Frau Holle rings a bell. This story from the Brothers Grimm collections is quite similar to the already mentioned Diamonds and Toads, and may have been the inspiration for the story OP heard.

@Valorum According to the Memory Alpha article you linked, Krasnovsky was introduced as a "Star Ship Captain": "He was to have been introduced, in dialogue from the final draft script, as a 'Star Command Captain', though this was changed to 'Star Ship Captain' in the revised final draft." Wouldn't that mean that he actually was Captain of a Starship?

"Isolation rooms" might be just what the term says, rooms to isolate people, for example in case of contagious diseases. On a spaceship that "boldly goes where no man has gone before" - who knows what germs you may encounter. In later eras, like TNG, there were force fields galore, probably even for this purpose. But in earlier eras, specified and pre-prepared rooms would make sense.

@Valorum Similar for Germany. There were three publicly operated channels. The first is a joint channel by the regional public radio broadcasters, which to this day calls itself "Das Erste", "The First (program)". The second was started in the 60s and is still called ZDF - "Zweites Deutsches Fernsehen", "Second German TV". And then there was one regional channel for each area, operated by the aforementioned radio broadcasters. Those were collectively called "Die Dritten", "The Thirds". Only in 1981 the highest German court ruled that private channels were legal, and 1984 the first one started.