Hello, there is no doubt that it is very risky to connect a 220v device to a metal fence. and more if as I understand, you made the connection, I do not know if I am wrong, because the companions present do not mention it, but in your description you indicate that you carried a red wire from the bell, to the button, and from there to the neutral, and the other red bell wire, to the phase. This indicates that the phase is directly to the bell, which, by the thrown of its coil, keeps all the line in phase, that is, the feeding, direct, is in phase, and the return, also, which is doubly risky On the other hand, I consider that you should check very well the isolation of all the components from the cables, which do not thread anywhere with metal parts, to the bell that is perfectly well insulated in its electrical parts, from the housing that contains it . However, I think that as the partners tell you, it would be best to change the canpanilla to a low voltage one, because that way you avoid all the risks, greetings