Safety Rocker Power Switch Key

I keep losing these stupid keys. Which is really strange since I rarely if ever take them out of the machine. You can get something similar from Amazon (2 for $12). But I figure this is why I bought a 3d printer anyway.
This could probably use a few tweaks. I think the ends of the key may need to be beveled just a little to aid in sliding in, and maybe a friction notch somewhere along the key length. I tried it on my Bosch router table, and on my Porter Cable drill press and it worked fine