I am hiring an electrician to do the work so my question is more for my education and helping me ask the proper questions to the perspective contractors.
Purchased a condo recently and want to put in some recessed lights. The condo has a subpanel in the laundry room with the main service panel in a common area on the main floor. All the current wiring is run in metal conduit, I presume that it's THHN wiring. The subpanel has a neutral bar that's not bonded to the panel. The panel is grounded via a grounding wire that I would presume runs to the main service panel. There is no ground bus within the service panel.
So, my question. For the new recessed lights (6" LEDs), can one run nonmetallic sheathed cable (NM cable) not in conduit? Or must this be THHN in conduit. If one runs NM cable (again, not in conduit) would you install a ground bar in the sub panel to bond the romNM cable ground to it, or can the NM cable ground be bonded to the metal electrical gang box (ground clip?) that the switch will be in? In this case the switch for the new lights could go into an existing metal gang box (where there is currently a switch for a ceiling fan). This box has metal conduit back to the sub panel. So from the panel, NM cable to the existing switch box, from there NM cable to the recessed lights. I am wondering if this is possible, would one / should one install a ground bus in the panel or bond ground to the existing switch box.
I hope this makes sense and I just didn't completely confuse everyone.