We are preparing to plaster up the hole in the wall left by the metal box that contained the previous thermostat console. I was thinking of doing this by first building up a layer or two of undercoat bonding and then applying plaster. However, there is a weak looking wooden batten directly behind the hole that needs to be filled: The original thermostat box was screwed onto this wooden batten. It feels like it is not attached to anything on its right hand side situated behind the wall. What on earth should I do about this before commencing with the undercoat bonding? Cut away the batten? Or insert chicken wire in front of it?