Video: If you ever feel the need to make your own salvaged part trip wire alarm, it turns out it's a pretty easy process. Over on YouTube, Node walks you through it. All you'll need is a piezo buzzer, a 9-volt battery, a piece of plastic, tape, fishing line, an elastic band and a couple of small wires. Once your materials are gathered up, you'll wire everything together, wrap it in tape, then mount it to the door. When the wire is disconnected, it will sound the alarm. Obviously this isn't terribly necessary in everyday life, but it is a fun little project that teaches you a bit about electronics while giving you a tool that will hopefully never actually be useful. Head over to YouTube for the full guide.