This can be easily done without connecting neutral to the switch. This connection is violating the rules and not at all safe. If the lamp in off position, it's completely disconnected from the phase wire. But here it's both terminals are live and lamp is in off condition. Stupid.
this circuit is called in Germany "Hamburg alternating circuit" and has also been strictly prohibited in the USA since 1923 according to NEC Article 404.2
this circuit is called in Germany "Hamburg alternating circuit" and has also been strictly prohibited in the USA since 1923 according to NEC Article 404.2