It would be nice if your 3D printer could spit out PC boards. There’s been lots of work done to make that happen, mostly centered on depositing conductive material, although we’ve been surprised no one has worked out how to just 3D print a plastic resist mask.
We recently found a GitHub group for [PCBPrints] which has small modules that would be useful in prototyping and breadboarding. They are really just carriers that create plug in modules for switches, LEDs, and the like. It looks like this is a aggregated list of other GitHub projects that realize these designs. The group is in Spanish, but Google Translate is your friend, as usual. You can see a video of one of the button modules in action, below.