Prepare Toilet Switch Wire

Wire nut together all three neutrals.  

Make sure to twist about 2" back for a good connection.

Gather all of the ground wires.  

Clamp them together about 9 in back. 

Cut back two of those wires. 

Twist at the connection about 2" back.

Separate the wire that is coming from the fan so that it is by itself.  Make about a 12 " pigtail and wire together with the two wires that are not the fan. 

 Rationale:

One of the wires is bringing power from the load center and the other is carrying power to the other switch box. The pigtail will take power to the switch, and the switch to the fan. 

Twist together the pigtail fan line wire.

When we install the switch we are just breaking the connection between the power and the light.

Stuff everything back inside of the box.