There are three main types of nail guns used on construction sites: compressed air guns for factories, butane gas guns for on-site use, and lighter electric guns. Nail gun accidents are common and usually fall into categories like operators shooting themselves due to improper stance, maintenance errors, carrying guns with fingers on triggers, hand positioning too close to workpieces, or deliberate stupidity. Safety features like nose guards and trigger releases are bypassed in many accidents, so proper training, supervision, protective equipment, and incident investigation are needed to control risks from nail guns.