When I have a long carve on my Shapeoko CNC or 3D Printer, I like to remotely monitor it to make sure everything is going smoothly. I'd like to say, " NEVER LET YOUR CNC RUN WITHOUT YOU THERE!", but lets be real. We've all done it.
What i do is have this camera set up so I can periodically check in and make sure everything is cutting fine. In the event of a catastrophic error, I pair the camera with a wifi outlet. I have my CNC and Router plugged in to the wifi outlet and can shut if off anywhere I have internet or cell reception.
Click the two links on the right to buy the same products I use. It's a small price to pay for piece of mind.