Hello, Ralph.
In the book "Otherwhere", Kurt Leland suggests that sometimes we get lessons in how to recognise that we are dreaming, so that we learn how to get lucid. In these kinds of dreams or testing scenarios the dream gives us hints that we dream. Also we are made aware that our thinking directs the content of the dream.
First you have a ghostly experience. This would make people question the reality, but with good old dream logic you conclude at some point it is a burglar. Also, the conclusion that it is a ghost was you.
So, now you have the tools to surprise the burglar, and tada! There is a "burglar". The burglar is weird, and gives you a weird explanation. Dream logic again - instead of recognising the weirdness you accept the explanation, even though in a total context it does not really make sense.
After you get more immersed in the dream, more people show up. I think the possible scenario fades here.
I think the clown costume might have been to emphasize the absurdity the claim she makes. Like her outfit says "Isn't what I say truly hilarious if you think about it?"
After you concluded it was a ghost, a female figure appeared to you, flashing by. After you concluded it is a burglar, you catch a burglar, after you accept the idea it is a friend, more friendly people show up. It seems like every time your expectations drive the further story of the dream.
On the other hand, never do you question the fact that you go asleep while a ghost or a burglar might be around.
Just some thoughts.
Be well