Ghosts showrunner Joe Port addresses whether the sitcom could ever have a crossover with the original BBC series that inspired it, as well as his hesitations about bringing the two casts together. The original series saw a young couple inherit a stately, decrepit home from a recently deceased relative, only for Allison (Charlotte Ritchie) to see long-past residents of the land after a near-death experience, leading to plenty of hijinks. The US incarnation was developed by CBS, with Rose McIver taking on the role of Sam, who goes through a similar experience and begins to see her own ghostly acquaintances.

https://screenrant.com/ghosts-show-crossover-uk-showrunner-response/