I'm having a hard time finding a local place to buy contact sensors, so I guess that's the first question. I struck out at Lowe's, my local hardware store, and a local Overhead door place. Any suggestions?
Online, I found this option: http://www.smarthome.com/7040/SECO-LARM ... pen/p.aspx, but they also have a "normally closed" version, and I'm not sure which is the right one for this particular application.
Thanks! Hoping to work on this project this weekend....