The SyFy channel did this actually.
Vault 106 a.k.a The U.S.S. Explorer
The Sole Survivor arrives at yet another Vault and hacks into it, only to immediately be surrounded by people in Naval uniforms and space suits looking entirely panicked. You see, in Vault 106, they were given the task by the Enclave to test to see how people would respond to a 200 year journey to Alpha Centauri. The entirety of the Vault is thus made up to look like a spaceship with the locals maintaining machinery meant to mimick the journey.
The current Overseer isn't as fanatical as previous ones and the journey is supposed to be ending anytime now but they've been "delayed." They'll also be horrified to discover the US government hasn't rebuilt the world yet. She's also ashamed of her ancestors who maintained the fiction for so very long but terrified of what the citizens will do if they find out. They beg the Sole Survivor to pretend to be an astronaut sent on a similar mission and offer a home here as well as currency (you can request caps instead).
You can find the people are suffering an immense case of cabin sickness as the Vault feels futuristic and beautiful in a Pre-War way even as there's things like class divisions, a brothel (men and women), and more. The PCs can help the Vault by choosing:
1. To tell everyone via speech checks.
2. To convince everyone the world they were going to inhabit is crap and they need to make a home journey.
3. To sabotage the illusion in a dramatic way, which leads to a riot.