To quote a recent response to someone else, on a similar topic:
Reading radio signals in your own Python code and then sending resulting commands to the autopilot would require some roundabout passing around of information, and may increase communication/control latency to a problematic degree.
It’s likely worth looking at the RC_CHANNELS and SERVO_OUTPUT_RAW MAVLink message details to see whether the noise is coming from your radio hardware (including potentially your controller), a misunderstanding of (or bug in) the autopilot, or (otherwise) is occurring at the output pins / is being picked up by the wires to the ESCs.