I installed a light fixture in my bathroom and need help grounding it properly. The previous fixture wasn't grounded. When I removed the fixture, there were two wires, one black and one white, from the wall while the copper, ground wire was wrapped around a screw that was screwed into a metal plate type thing. Do I connect the ground wire from the fixture to the end of the copper wire wrapped around the screw?
Yes, if there is a ground lead from the fixture you must connect it. If the box is metallic, and properly bonded, then any metal crossbars or mounting will also be bonded, but do connect the ground wire to the box's ground wire.