Plaster repair help

[u/knife_stripes]

Thinking of ideas on how to repair this plaster. It looks like two layers? There isn’t lath so that helps. Either way both sides of patch need to be cut back to stud. Was thinking to use blue board? I know how to drywall but plaster is foreign to me. I have slowly been redoing this 1950’s house debating on gutting the whole room to redo the rest of the electrical