UR 12 Hum is a Grounding Issue

I’ve Read quite a bit about buzzing and humming in the audio signal. unfortunately I’ve come across no feesable solutions yet. I’ve noticed that if I put my bare arm on the metal Chassis of the unit. The buzzing all but disappears. But that’s not very practical when I’m trying to play an instrument and navigate Cubase.
So far The only hands free solution is to use headphones to listen to my recordings, and stick the lose ends of the RCA wires that are plugged into the L and R outputs on the rear of the UR 12, into my sock. this also grounds out the buzz in the signal path.
I would appreciate any suggestions as to how ground out the casing of the USB interface in a way that is more permanent and less confining to my movements.
Thank You for your Quick and Knowlegable Responses… Wow I assume alot. I will Keep any interested parties posted to ant Solutions I personally come up with.

Hi! Im facing the same issue.
Im using UR12 and I received hums coming from my guitar. I did the exact same thing as you. Every time i touch the metal housing of my cable, the hums goes away. Previously I didn’t have any issues on this. I tried changing my cables and the hum is still there.
Currently im using Mid 2012 Macbook Pro El Capitan 10.11.3
I’m still hoping for a solution

Same problem here, awfull buzzing once the guitar is plugged in…when I touch the metal casing of the cable the buzz is gone, but I only have 2 hands and need them both while playing guitar.

Another issue is the line output on the backend of the UR12. I connected some older speakers directly in the output, they work perfectly, but the volume is very low.

Any sollutions on any of the problems???