I have two small children that love to visit me in my workshop. My worry
has always been that one day they may visit the shop when I'm not there and
some how turn on a machine and feed their hands in. Right now I keep the
door locked and ALWAYS unplug the machines.

I want to add another level of safety by putting onoff / key switch
controllers on all the machines but mounted on the wall well out of the
reach of any child.

Has anyone done something like this and if so where is a good place to
purchase the equipment.