Patch holes on engineered wood (masonite) siding and mounting security camera
You could use this Exterior Post Top and either paint or stain it before installation. It already has a hole drilled in the center where you can run the wire through. You can also use the siding groove (where the holes are drilled) as a raceway for the wiring. This will prevent you from pinching the wire when you affix it to the wall. You can fasten this plate with two or three screws in such a way that your camera would cover them. All that would be left is that tiny hole at the top where the screw is. Just caulk that and touch it up with some paint.