YES...you can, only if your an experience qualified electrician.
Many reviews are about people complaining - what to do with all the extra wire.
You can cut the wire. Not sure on how it will effect the warranty of the camera.
Even though Paula - I would not recommend using an existing electrical power source.
Technically you do have to use the USB hockey puck that converts 120 volts in able to make the camera work, and that will not fit into the electrical box.