I have a question about what to do with ground wires.
I am installing a new light fixture above my dining room table. Fixture comes with a ground wire obviously. Main electrical wiring has the normal black and white wire AND a bare copper wire (which I’m assuming is another ground wire).
In addition it appears that my octagonal electric junction box also has a green copper ground wire attached to box with a screw, so I now have three grounding wires. Light fixture mounting bracket has the normal green screw that I should be attaching a ground wire.
Question: Is which wire do I attach to the mounting bracket ground screw AND what to do with the other grounding wires??