A friend suggested that a 3-way off switch might possess enough novelty to warrant a patent.  I have no idea.  I hope that it’s not actually patentable, because I just want to see that a product like this is made, but I actually have some concerns because of my situation that the government would take my idea and give it to a contractor, or patent it themselves and sit on the patent.

Congratulations! By publishing this article, you have established that you thought of this idea in early 2015. While you may decide to patent it yourself, you no longer need to fear someone else patenting it, because one must have a good claim to inventing a thing in order to obtain a patent on it.