Depends on how much amperage your pulling in that box.
I installed an additional 8 CB box so that everything could be on a home run circuit, so my amp draw is small. I hate fuses
, CB's are much better in my opinion. since amp draw is small I tied into the buss bar of the original panel.
I added things like a Wirie Pro, cockpit
lights etc. and other such low amp stuff but I wanted them on their own circuit.