Hello @Solla-topee In fact, I verified the white wire, confirming that it is the neutral one. I placed the HS210 switch in the other box of the same line lamp, and in other two simple boxes (that do...

I have a TpLink HS210 three-way Smart Switch, all the switch boxes in the house have two-pole wiring, phase or positive (red) and neutral (white), there is no ground. I already did tests by...