Today, I was searching online for a cool project to do, and that’s exactly what I found. AaronAlai made an Arduino EMF detector. It uses, well, an Arduino board, a piece of wire, a resistor, and an LED. I built it, and I went around my house searching for electromagnetic fields (or ghosts!). Very spooky when doing it in the dark! A very simple project that does something very cool. I recommend it for beginners.