Add a switch to an overhead light
Sounds like you want to control the overhead light with a switch that's on a different circuit.  You can use an "in-line" switch such as this one which fits inside the ceiling electrical box.  You'll need a compatible wall switch to send the commands to the in-line switch which actually controls the load.  There are probably a number of other technologies and manufacturers, I'm just using this as an example.  If this is your first or only home automation project, you'll want to be sure both circuits are on the same 120 volt leg to be sure the signals get through.