Replacing a single switch with a double switch
We have a typical single lamp exterior fixture on the patio with an interior wall switch. We would like to install a floodlight next to it to illuminate the whole yard. Can I just pull the existing wall box out and replace it with a double-gang box and switches, then (hopefully) fish the new wire for the 2nd fixture through the same route as the existing wire? The house has 1958 vintage ungrounded wiring.