I have a Nutone exhaust fan/light fixture in my bathroom. The fan and light are each controlled by their own 2 pole switch, one is inside the bathroom and one is outside. I want to replace the combination fixture with a light only fixture. I would like to replace the switches with 3 poles so the light can be controlled from inside or outside the bathroom. Is there a way to wire this using the existing 2 conductor Romex? All conductors currently come into the junction box in the ceiling.
Short answer is: No
You can't use single pole switches (what you referred to as 2 pole) to create a 3-way circuit. You need another wire that is not available with 2 wire cable.
You would have to replace the 2 wire cable with 3 wire.
However they do have "wireless" switches that convert a single pole switch to a 3-way setup with the wireless switch at the second location. You might check into that.