And make sure you lock the switch in place (or the cover for the switch or breaker box) so no one can screw with it; you should also pull the main fuses if there are any. And for heaven's sake, please make sure that all flammable chemicals like paints solvents, etc. are either removed off-site after the work session is over or are locked in a cabinet designed for the purpose, and that all rags, brushes, and paint rollers used with these materials have been properly cleaned and allowed to dry or are properly disposed of off-site; quite a few structures have gone up in flames because some idiot left a bunch of oil, paint, or solvent-soaked rags sitting in a corner that spontaneuosly ignited, plus a would-be vandal or arsonist could use those materials to cause damage (or worse) if they're not locked up or removed.