S17E15 Homer Simpson, This Is Your Wife
When he sees the new plasma screen HD TV Lenny got, Homer stays at Lenny's place watching TV for some days which makes Marge decide to try and win a plasma screen HD TV for themselves. She doesn't win the TV, but the family does win a tour to the FOX studios. There Homer is told about a wife-swapping show which would make him enough money to buy the TV he so desperately wants. The Simpsons swap wives with the well educated, well-to-do Heathbar family.