My garage light has one set of wires coming from the light. I have read this is called a switch leg. The switch is located in the garage outside of the door. I want to add a switch just inside the door so that my wife can turn on the light without opening the door (security wise). Can I turn this switch leg into a 3way where both switches work this light or do I have to just wire inside and leave outside dead. If so how do I wire it? Thanks.