American Horror Story: Murder House, an odd question about Moira (open spoilers)

So I just finished the Halloween episode of season 1, and have kind of an odd question about Moira the housekeeper. So ever since Constance killed her she appears a matron with a weird eye to women, and a sexy vixen to men. So how did she appear to the gay couple that preceded the Harmons when she worked for them? :confused: She’s a matron when she’s talking to Chad at the end, but he’s already dead by then.

Well I finished season 1 and didn’t get an answer. Or any explanation as to why Moira’s the only ghost who’s actually aged since being dead. I wonder what happens to everyone if/when the house is no longer there. Eventually it’s going to get torn down or just collapse into ruins.

from the AHS wiki