How To: Maintain your home electrical wiring and fixtures

well, it seems john knows a little about what he's doing, however, if you are reading this you should hire a licensed electrician... the vacuuming out of the box and his reason for doing it naturally leads me to ask john if he plans to go thru the entire building and remove every device plate and suck all the cobwebs and dust out? if he claims there's some sort of hazard for the one device you're changing out, wouldn't the same hazard exist for ALL the devices?? over the years i've changed more devices than i can count and i never once vacuumed out a single box. also, what if you wanted to change out a three way switch? he only showed us how he changes a single pole switch (the ones with ON and OFF molded into the plastic)... three and four way switches don't have any markings indicating on or off... i'm sure the building he's demonstrating all this for us must have some three ways in there... c'mon john :) show us how to change out a four way and install a dimmer...