Hello and thank you for reading my question.
I have a duplex switch, one on top of another, where one switch controls a lamppost and the other switch controls outdoor wall sconces. I would like to control both switches with a single wall timer that turns the exterior lights on automatically. The timer I purchased has a green, white, black and red wire. The clerk at the hardware store told me I could simply combine the wires together by color with the orange wire caps that come with the timer. Will combining two switches like this work? Thank you.
Yes, combining the wires will make that work. This job can be a pain in the but for many DYIer and home owners. You may just want to call someone in and be done with it. The issue is that unless you are familiar with the wires in a switch box they can get confusing quickly.