In using a shop vac to vacuum in the garage on a cold dry day, I sometimes shocks of static electricity when I touch something that is grounded, like a work light or exposed wiring in the attic. I've also gotten static shocks from using an ordinary vacuum cleaner on outdoor carpet in a carport. I associate this problem with the mostly plastic construction of modern vacuum cleaners. Is there a simple way to prevent it? - some sort of anti-static spray?