Switches Controlling Lighting Loads. The grounded
circuit conductor for the controlled lighting circuit shall be
installed at the location where switches control lighting loads
that are supplied by a grounded general-purpose branch circuit
serving bathrooms, hallways, stairways, or rooms suitable for
human habitation or occupancy as defined in the applicable
building code. Where multiple switch locations control the
same lighting load such that the entire floor area of the room
or space is visible from the single or combined switch locations,
the grounded circuit conductor shall only be required at one
location. A grounded conductor shall not be required to be
installed at lighting switch locations under any of the following
conditions:
(1) Where conductors enter the box enclosing the switch
through a raceway, provided that the raceway is large
enough for all contained conductors, including a grounded
conductor
(2) Where the box enclosing the switch is accessible for the
installation of an additional or replacement cable without
removing finish materials
(3) Where snap switches with integral enclosures comply with
300.15(E)
(4) Where lighting in the area is controlled by automatic
means
(5) Where a switch controls a receptacle load