I specialize in wiring devices and timers.
You are adding a new light.
You need to wire a switch to the new light.
The existing box has a switch and receptacle.
Here's where I am confused:
I am uncertain if the original switch and receptacle are a single device.
Of if you have separate switch and separate receptacle?
And then:
What kind of device are you adding, a single switch?
Are you replacing the receptacle with a switch?
Or are you installing a double switch as shown below?
Add a comment and tell me the devices you are working with and the color of the screws on sides of each devices and I will get it wired correctly for you.
The double toggle switch shown above has brass screws on one side and silver screws on the other side.
The brass screws are connected by a brass plate.
The silver screws on the other side of the device are separate.
The hot wire connects to the brass screw.
The outdoor light connects to one of the silver screws.
The new light connects to the other silver screw.