Can’t think of an episode

I'm trying to find an old twilight zone episode. At least I think it's a TZ episode. A boy/girl and maybe their family are in a paradise of sorts. They're near a swimming pool. And there's a society underground that comes to take people from time to time. Is this a TZ episode or am I imagining things? I know it's black and white and I recall seeing it during a marathon about 30 years ago on New Years Day. Any help would be awesome.