We took out an old medicine cabinet/mirror combo that was above the sink in one of our bathrooms. That has left a large hole (26in X 21in) in the drywall where the cabinet used to be. Should I attach a piece of wood across the two studs on either side of the hole before screwing on a fresh piece of 26X21in drywall onto this cross piece? Or is it better to cut out some more of the old drywall to expose the two vertical studs and screw a fill in drywall piece onto these existing studs? I am concerned that the first approach may make it difficult to make the new piece be absolutely fluch with the old piece. Any suggestions on how best to fill this hole would be appreciated. thank you.....