I know how does a noise pedal work ... It cut-off the lower volume sounds (you controle what should be the point to cut-off signal of lower volumes when you set the parameters) like hissing sounds when high distortion is on and the guitar not played , which is lower than the notes you make sound.

I know it won't help if the noise happens while you're playing , but I just thought he/she might have noise problem when not playing too ... Usualy you get more noise when you turn the wah on , so I suggested that he/she tries a noise pedal to see if it help.
That's all.