Halloween Spirit Picture

Theresa E. from Chicago might have captured the presence of a spirit being on Halloween!
"Halloween Party 2006 - orbs in my pics are very common and no longer a big surprise; but, this one is very different. Does anyone agree?"

Here's the thing: cigarette smoke can cause a similar, spooky, misty effect in photographs. It is a good thing to note that second-hand smoke from cigarettes, cigars and the like can hang around for many hours within a non-ventilated building. Often times, people are not aware and believe the room is clear from this hard-to-see mist.  

But, as far as this photo, if no one was smoking, then there is no other explanation for the spirit presence or "mist."