Will this buck converter power my arduino?
Sure the standard 5V barrel adapter prongs could be shrink wrapped to the raw AC wires but that's not very clean.


Also very deadly.  DO NOT DO THIS!!!!  The Arduino will explode (literally. I am NOT joking here!!!) and potentially electrocute you.



Those modules you show are not "buck" regulators. They are SMPS modules - an entirely different thing.

Yes, one of those would be suitable for powering an Arduino from a mains supply, but given your supposition above I rather suspect your skills and knowledge would make wiring it up a dangerous prospect.

Better would be to use a proper off-the-shelf power plug and have someone qualified install a suitable socket inside the enclosure.