“Before any part of the episodes are written, the guests are interviewed by a writer/producer. Originally, a Space Ghost costume was worn by Andy Merrill, one which he later made famous in some Cartoon Planet intros. More often the writer/producer appears in normal dress, but may still impersonate Space Ghost’s character traits and mannerisms. In many cases, the interviewee is alone in a studio, while the interviewer conducts the session over a speaker phone. In the all-black room where the interview takes place, the guests are told what basic directions to look in to “talk” to Zorak, Moltar, or Space Ghost. The interviewer also rarely reveals his actual name so that the guest is forced to address him as “Space Ghost.” This serves to both maintain continuity and to engender a sense of bewilderment in the guest.

After an interview is done, the writing team goes back over it, taking pieces out of context and out of order, then assembling them into the “responses” to Space Ghost and the rest of the show.”

– Wikipedia’s account of how interviews are conducted on Space Ghost Coast to Coast.