What's one of the most frequent culprits of energy inefficiency? Leaving on the lights. Master Builder Matt Risinger shows us a closet switch that will never let you forget to turn the lights off again. In the video, Risinger demonstrates how a simple switch placed within the door jamb will replace the need for a separate light switch. By installing this little switch, you won't have to worry about leaving the lights on, as long as you shut the door. Since the switches are only effective if you keep the door shut most of the time, consider carefully before you install them. A bedroom probably isn't the best candidate for a door jamb light switch.Speaking of door jambs, he also found a simple (and cost effective) hack to protect door jambs during construction. A reusable door jamb protector helps keep the house free of nicks and chips, especially during the finishing touches of construction.