I have 2 lights in my bathroom, one over the sink and the other over the shower stall. A separate switch controls each light. I would like to replace the shower light with a light/fan combo. How do I wire it to the existing switch position, replacing that switch with a 2-switch unit to control the light and fan separately? I plan to vent the fan to the soffit. Thanks, LAH

Need to research and explain exactly how the two lights and switches are wired now.

Since the shower light has it's own switch, installing a fan light will mean both will operate at the same time.

If you want to have the fan controlled separately by it' own switch, new wiring and a switch will need to be installed.

Also, be sure to check the instructions accompanying the fan/light unit. I am sure you will see that it will need GFI protection when installed above a shower/tub. This add more complexity to the wiring.