Disclaimer: I do not claim to own the X-Files show. This will not be continued.
"Cut!" David Duchovny and Gillian Anderson went back to their trailers after a day of shooting an X-Files show. They went to sleep for the night... to wake up in the same homes they had filmed in for the X-Files characters' home lives.
At first, they switch realities only when they go to sleep. Pretty soon, they find themselves in another reality every third time they turn around. Meanwhile, they slowly turn into their characters, Mulder and Scully. For instance, David starts chowing down on sunflower seeds and Gillian starts wearing clean pressed suits. Also, they develop into their characters' personalities. It doesn't take long for them to think that they were always Mulder and Scully. At the end, they wake up back where they started... ready to shoot for another X-Files show.