I have been clearing out my cellar making some space to do some homebrewing. Noticed a junction box with its lid(cover) sagging pushed the lib back up and it fell off. Looking ta the center screw the center screw is cracked so half is in and half is out. Am I allowed to switch of the electric to the ring (I have traced the wires back across the cellar celling to the consumer unit) and put a new junction box in? Or is this a step up from moving a socket so notifiable and thus means only a qualified sparky can do it. I could just squirt some araldite in the screw hole and put the screw back in but that seems a little shabby, how would a future electrician get in to the box. Would a future electrician need to open the box, been here 13 years and never had an electrician in the house ?