The house Sam and Diane buy is the same stage house used in S5 Ep20 (Dinner At 8:00ish) when Frazier and Lilith move in together.
This episode features guest actor Douglas Seale as Bert Miller, and Billie Bird as his wife Lillian Miller. In the story line for this episode, Sam and Diane celebrate Christmas with the Millers, with Sam posing as Santa Claus. The following year, Ernest Saves Christmas came out, with Douglas Seale playing Santa Claus and Billie Bird playing his love interest.