electricalwiring
Wiring Diagram
My Diagram of how the wiring should be. Can someone confirm the diagram?
Also on the actual switch box, there is currently three pairs coming. I.e. with only one hot. Why would there be three wires when there was just a light and switch before? I got confused after removing the original equipment.
You can't have one switch operate light OR fan. Many jurisdictions absolutely require that a switch on the wall near a room entrance, control a lamp. That is to benefit house guests and mainly from the government's perspective, first responders. There's an exception to allow a switched outlet instead, presuming a person is going to plug a floor lamp into that. There is no exception to allow a fan/light locally switched at the fan. (such things can exist, they can't be the only light). That said:
They now make gadgets to solve the "I have 14/2 and wish I had 14/3" problem. Each has a smart switch (typically 1-gang) with 2 controls, and a control module which sits under the fan shroud. The switch communicates with the module either via powerline networking or via wireless, and some of those are compatible with smartphones or integrated home-automation systems as are now emerging in the market.
If I understand your layout, you could wire it like this:
Chaining to all four lights like this requires the use of 12/3 cable for the first two sections, but if you want to follow Tester101's suggestion and add the extra conductor to the fan circuit for possible future use, you're going to buy some 12/3 anyway.
EDIT: Carl Witthoft is correct, the bathroom should be protected by a GFCI. I have altered my diagram to show a GFCI outlet with downstream protection.
Best Answer
The one hot is the supply to the switches and outlet your incoming hot should be a black wire that should be connected to 1 side of each switch and the outlet. The white neutrals are pigtailed together and feeding the humidistat, light and outlet. The grounds should be pigtailed and attached to the metal box. So 3 cables is correct: 1 for incoming power, 2 supplying the fan & light.