I've got this Mighty Brite AC Power Adapter which I use for my book light. However, right where the cord joins the plug that plugs into the light, it has frayed and separated. They've made it so the plug can't be repaired. Are these kinds of plugs for sale someplace? I've already tried Radio Shack in town. They had nothing like it. It's kind of hard to google it since I'm not quite sure what it's called.