I'll be hooking up three lights on the same circuit. Two of the boxes will have two cables, the third last one will have one. What is the best way to hook up the ground wire on the light? Do I hook it up to the electric box or screw it in with the other ground wires.

 

1. How are the voltage and amp of the power? (AC/DC)
2. What kind of the circuit?
3. What kind of the lamps of the lights? (V,I)