Yes it is. Importing a cheap Chinese WiFi access point that has an exploitable default password should be as illegal as importing Chinese fentanyl.
That's ridiculous, why? I'd understand some sort of certification process and requiring certified products to have ample warnings but why should it be illegal? If I want to buy cheap hardware or software that isn't certified I should be able to.
Both such devices do as much if not more harm to your neighbor as to you. An electrical appliance that interferes with TV broadcasts may not bother you but it bothers your neighbor. An IoT camera that's hacked to DoS a hospital may not bother you but it bothers the patients of the hospital.
In some fictional Libertarian wonderland, these problems could be dealt with neighbors suing neighbors but in the real world we need the state to regulate products with serious cost "externalities".