Hi there. I have a pickup on my double bass's bridge, and currently have 'dangling wires' when I plug my (wireless) input into my pickups. I am seeking some type of bag, or satchel, if you will, to hold my wireless input, similar to this image.
That looks like a shortish bow quiver that has been re-purposed. I know I've seen ones like this, but can't remember where... Maybe check the Lemur and Gollihur websites...
I once tied my Schertler preamp to the back of my tailpiece with shoelaces. Took it off after two minutes. The weight had an amazing and horrible effect on the sound of my Geiger.