Purchased a wall light fixture that came with a bracket that gets attached to the metal box. The ground screw is on the bracket. There is one 14/2 wire in the metal box n ow with a ground. Wrapped the 14/2 ground wire around the cable clamp screw. Does the ground wire from the light fixture also need to be wrapped around the cable cable screw? Either way or something else? Also do all of the wires have to be pushed back in to the metal box behind the light fixture bracket or in front? Either way? Thanks.