well, one mozzie zapper finally worked with my wire test but then I accidently touched the LED and the electric kill bars and it exploded the power wire inside the unit with a bang " and my circuit breaker went off.
so that one is fried .... I don't think the other one works, so I'll just throw it in the trash like all the other Shopee gear I buy.
No refund required, I destroyed 1 unit, so not worth claiming on the other.