Electronics sold direct to end users must comply with FCC, CE LVD/EMC and other regulations. The vast majority of the hobby market ignores this though, and they don't get enforced much except for intentional transmitters.
In the US products with switching frequencies faster than 9 khz are supposed to be tested for FCC part 15 compliance but you are not required to have CE or UL testing.
However most retailers will not carry a product that does not have a CE or UL mark
