A new study commissioned by the National Association of Home Builders revealed Friday that 74 percent of home contractors end up accidentally walling themselves in when constructing or renovating a residence. A review of home construction projects since 1995 shows that in roughly three of every four cases, workers inadvertently erected drywall or laid bricks and mortar around their bodies, trapping themselves inside the barrier where they remained until someone heard their desperate cries for help, said lead researcher Mark Vander, adding that, on average, there is a minimum of three contractors stuck inside any given newly constructed home. During the building phase, many workers accidentally put the last piece of Sheetrock into place before realizing that theyve made a huge mistake and didnt provide themselves with a way out. Without any doorways or other exits, the contractors roam inside the walls frantically searching for an escape, sometimes for up to several weeks or months. The study also found that entire construction crews are often trapped on the top floors of skyscrapers because they forgot to build stairs. 