Cutting Open a Stop Light to Find Out What’s Inside by Justin Page at 9:27 AM on July 18, 2017 FacebookTwitterPinterestTumblrFlipboardMorePrintPocketLinkedInTelegramWhatsAppSkypeReddit Father and son team Dan and Lincoln Markham of What’s Inside examined an actual stop light and then cut it open to find out exactly what is inside. We CUT OPEN a Stop Light!! Super interesting!! This was really interesting and educational! Always wondered how traffic lights work!