This is lighting diagram for a room. The existing wiring (Lamp A) is a switched loop. The switch is a combo switch (Blue Box) and I want to use the unused second switch for the new lamp. What I want to add is in the orange box. (Lamp B)
All the wiring is in the attic which I can access.
Since this is a switched loop, the terminals at the existing switch are hot.
I have the black and white wires running to the unused switch.
Where do I connect back to neutral?
Are there any wiring diagrams for this arrangement?
How should I wire the new switch and wiring?