WallCakes, you seem to understand perfectly...how perfectly nutz this situation is!
Something else to consider about those switch plates: Would they be considered PRIMARILY for a child's use, as opposed to use by anyone? Even if they are intended for a child's room, I think you could make the argument that a light switch is not PRIMARILY intended for the child, so the plate would be for the "general audience". If true, then the CPSIA would not apply!
That's the same situation as those buttons you mention: testing not required by manufacturer because they could be used on anyone's garment. If, however, you use them on a child's shirt, they become CPSIA-related and must have test results.