I just added a toggle switch to my fridge for the heating strip. It's a SPST and cost like 5 bucks at Radio Shack. As I can never remember which is the on position for those I/O switches, I chose a lighted switch.
I figure the heating strip will use more power than the switch light, so what the heck. I may add a label on the bottom of the clear lens describing what the switch does (Refrig. Heat Strip). That'll help the next owner.
It's a pretty tight fit in there and not much spare wire to work with. My switch is deeper than KMH's, so with the wire connectors on the switch the festoon refrigerator light won't fit.
I've ordered a LED bulb, but don't know if I'll use it. As the refrigerator isn't that deep, that light really doesn't do anything and I have a ceiling light right over it. If I do decide to use it, I'll remove the wire connectors, then trim the terminals and solder directly to them. That'll give me the room I need.
The whole refrigerator light/switch assembly is held on by what looks like 2 plastic rivets (you can see 1 in KMH's pics). I don't recommend removing this assembly as you'll probably break those rivets in removing it and have no way to re-attach the assembly, other than using a screw.
Here's the answer on the I/O switches-
"It has to do with binary numeral system. 1 for on, 0 for off. This way it's understandable for everyone around the world, since not everyone understands English (ON/OFF)."
That's great IF you understand the binary numeral system.
Rick