How best to repair a botched light fitting in plasterboard?
If you can put a piece of wood in you can put a screw to hold the wood in place (putting the screw under the fitting so that it is not visible) and then put in another screw at the normal location. You could remove the screws that are in place just to hold the wood after if desired as once your fitting is up it won’t really matter. The longer the wood the more stress it will take.