I built a homemade paint booth in my shop out of 5 mill(I think)plastic and used an attic exhaust fan to pull out fumes. I accidentally forgot to move my truck that was outside the door one day when painting, but to my surprise had no overspray on it. If you are concerned, you could cover your exhaust fan with A/C filter material. It will catch most of the overspray as the air exits. I did this to keep paint out of my efan motor.