Spoiler Alert for Ghosts season 4, episodes 8 and 9, “A Very Arondekar Christmas”Ghosts season 4 has a massive holiday special that changes the landscape for Jay, Sam, and the spirits at Woodstone Mansion. In the two-part Christmas special, “A Very Ardondekar Christmas,” things get interesting when Jay’s parents come to visit. To worsen already complicated dynamics (or maybe help them), Sam and Jay are both possessed by ghosts after they electrocute themselves. When Nancy and Pete take over Sam and Jay’s bodies, respectively, Pete’s possession presents a new conundrum for the cohort: Pete can’t be expelled through the ghost boundary due to his non-geographically bound ghost spirit power.

https://screenrant.com/ghosts-season-4-jay-twist-importance-to-sams-marriage-explainer/