Last time DH's tire blew out, we were in a wildlife area and it sounded like a gunshot! Everyone flinched, dove off their bikes and were halfway to the ground when we realized it was his tire!

As for the house--it usually takes days to find the strange sounds. As my sister says, that's why you should have a pet--just blame it on the cat! The most common is a piece off the overhead kitchen light that falls at random.

I didn't have a skull, but had a book of ghost stories that travelled our college dorm. Every time something strange happened, it got passed off until it turned into a soccer game in the hallway. It's why I don't own a ouiji board!