connect the wires, place in moisture resistant 'box', then press into the back of the wall box.
cut a rectangle of ply and 'interference fit' it into the box, a few mm below wall face. skim over, sand back, skim over again, sand and feather, prime and paint.
roughening and soaking the ply helps with adhesion of plaster
Wago connectors are considered a good option, put them inside a Wago box. You need to have the cables secured at entry and exit of the box which the wago does.
connect the wires, place in moisture resistant 'box', then press into the back of the wall box.
cut a rectangle of ply and 'interference fit' it into the box, a few mm below wall face. skim over, sand back, skim over again, sand and feather, prime and paint.
roughening and soaking the ply helps with adhesion of plaster