You have already solved the problem. If touching the rigging wires makes it go away, moving the antenna most likely will not fix it because the RF still exists. On pull pull systems for Giant scale rudders I always place one wire inside a section of push rod tubing, that way the wires cannot rub on each other.

So I would take a piece of tubing and cover one wire right where they touch inside the fuselage.

Plastic soda straws work well also

An easy way to install the tube is to slit it then "snap" it over the wire. It must be long enough so that if the tube slides on the wire it does not slide enough to allow the wire to rub again