Please disregard my question about you moving from nrf > RFM69, I load the oldest post and got my answer.

Hi napo7,
First off all congratulation for all the work you did so far and the sharing! I'd be glad to discuss with you directly (I'm French too ;-))

I'm also in the process of designing such kind of board.
I thought of using a standard Legrand derivation box (sorry for the awkward translation but I mean "boite de derivation" in plain French). This kind of box are dedicated to this kind of purpose, hide live wire that would be exposed otherwise.
I guess 3D printing is not a bad idea in essence but it's not secure; in my opinion it would melt too easily in case of electrical disorder on the 220V parts.

Other question: Why are you moving from nrf to RFM69?

Congrats again dude, you rule!

Cheers,
Marc