Um... what? i'm confused, but I think what you are asking is:
Do I think that the things I don't believe in, if they did exist, would be a part of "our" reality or external to it?

In which case, my answer is "either", I think of the two unlikely things an external spiritual force is the least unlikely (most likely) since I'd expect a built-in spiritual thing to be easier to spot, but I really don't care.