The Twilight Zone - Twenty Two

Lying in her hospital bed, professional dancer Liz Powell has a recurring nightmare where she takes the elevator down to the morgue wand is invited in by a severe looking nurse. Her doctor assures her there is nothing wrong with her physically and that she's just overworked and a little tired. The nightmare is very real to her and the doctor suggests that she try to break the pattern to see if she can them to stop. The next time she has the dream, she travels down to the morgue but the dream goes off as before. She's eventually released from hospital but it's only when she gets to the airport that it all starts to make sense