Hello! I'm going to be running a fused spur, it will be taken from where there is currently a standard double socket. In the interests of efficiency (ie laziness), I am wondering if a combined fused spur and single socket unit is available that would fit in the same back-box as the current double socket. I've never seen such a thing, and I'm guessing I'll have to install a new box for the spur, but I just thought I'd ask! Cheers.