She occasionally appears as a ghost later in the series.

He realizes that his girlfriend only appeared as a ghost.

After this, he appeared as a ghost multiple times between 1994 and 2001.

Deceased by the time of the story, but (supposedly) still appearing as a ghost.

Calvin appeared again as a ghost in February 2011.

But my favourite is when I appear as a ghost on the station platform in the final film.

Paul only appeared as a traditional ghost because he wore a sheet over his head in an attempt to look ghostly.

Hector appears as a ghost, talks to Molly and witnesses these events.

Perhaps it is you that appears as a ghost to me.

Church appears as a ghost for portions of the show, and he needed to appear transparent to the viewer.