That was the other answer I was going to give.
Say whatever you want, but don’t goose it. You could well wind up with a handful of sheet.
“Mel Gibson’s career, I presume?”
Nah, they’re only interested in folks living there.
As for the rest, it would depend greatly on the context. Is it the ghost of someone I knew? In that case, I’d talk or otherwise interact with him or her as I normally would with that person. Otherwise, I’d probably just say something introductory like “Yes, can I help you?”, and take it from there.
I dunno, but I think I can trump you…I saw one where this one stud was trying to get Hitler’s ghost to materialize. “I command you to appear!”
You can bet, if I were der Fuhrer, I would certainly obey orders from some guy wearing capris, with his hat on backwards!
Best wishes,
hh