AC to DC converters for ESP32

[Tommmmms]

Hello,

I will be using the ESP32 to dim an AC mains powered light fixture.

This means, the ESP32 can be powered by a 3.3V generated by a 110AC->5VDC power converter followed by a 5V->3.3V LDO that I already have on my ESP32 breakout board.

Questions:
1. If I plan to commercialize this product, should I keep the 110VAC->5VDC power circuity on a separate board than the ESP32?
2. I see a handful of cheap 110VAC->5VDC on Aliexpress for <$1 shipped from China. Anyone familiar with these AC->DC converters and whether those have a chance of passing the UL tests

How would you approach instituting this 110VAC->5VDC on the IoT system. Would you rather self-build the power circuit on the same PCB as the ESP32 or would you instantiate an UL-tested standalone power module on the same board.

I appreciate your help in advance.

Thanks,

Tom