I sincerely doubt it is the servo. I sincerely doubt it is the servo horn also. I have seen the dubro horns strip as Bob has mentioned but never a JR horn.

I an wondering if you are using two spearate channels to control the aileron's? If so something is active as mentioned above. When using two channels to control aileron's you need to inhibit the slave channel under screen 17 on the 10X. Not sure which radio you are using, but my guess is the slave channel is not inhibited and a knob or something is getting bumped.