Early live TV “story-within-a-story” twist: “Tales of Tomorrow” episode: “The Window.”
In 1952 people were still trying to figure out how to use the brand new medium. This episode stands out for playing up the potential.
https://m.youtube.com/watch?v=FE5Ft6GS-Fs&pp=ygUcdGFsZXMgb2YgdG9tb3Jyb3cgdGhlIHdpbmRvdw%3D%3D
https://m.youtube.com/watch?v=FE5Ft6GS-Fs&pp=ygUcdGFsZXMgb2YgdG9tb3Jyb3cgdGhlIHdpbmRvdw%3D%3D
According to a commentary HERE, there was supposedly a disclaimer attached to it, but no known surviving recordings of the episode show it. And apparently it was interrupted midstream in a few US cities by stations thinking it was real.