SME 20/2 Finger Lift Hum

On my SME 20/2 fitted with a Lyra Argo i, there is a hum whenever the finger lift is touched, but very quiet otherwise, and importantly, when the record is playing. Has anyone encountered something like this and figured out how to correct it. All possible ground combinations have been tried with no change. Again, the hum is only apparent when the finger lift is touched. Thank you for your help.
Dear Dover, If you re-read the thread you will see that every single point you made has already been made, and your "theory" has already been proposed. At least you and I and others agree. Insulating the finger-lift has apparently worked to eliminate the hum; the OP is not totally happy, however.
Lewm, not quite correct. Additional observations were
I was explaining to the gentleman why touching the SME armtube did not induce hum - anodising.
Provided additional options for insulation on the arm for aesthetics - get a painted one or use heatshrink rather than plastic.
Rubber shoes/mat I cant see anywhere - a bit off the wall, but I have seen this work.
I refrained from suggestions like removing his pacemaker or turning the cellphone off.
I have also seen hum issues or rf issues where there have been poor solder joints in the cable loom between the cartridge phono input sockets that whilst hum is not present, touching the arm induces it - not a ground loop issue, more of an antenna effect.
I like the heat shrink option (if I can't eliminate the hum source) for better aesthetics and will also check out the rubber shoes/mat just to see what happens (more evidence).
Rsnoceanview - good luck, I know how frustrating this can be.
Like Peterayer, I didn't install the finger lift on my SME V when I had one years ago, for the same aesthetic and sonic reasons.

I never use finger lifts anyway: that what the tone arm's cueing lever is for!