Do I need exterior rated electrical cable to add a house mounted electrical outlet or disconnect switch
If the cable is concealed entirely within the wall, then non-metallic sheathed cable (NM) is fine -- the inside of a wall cavity is dry unless you have some serious problems with your house!  You only need underground feeder cable (UF) if the cable's buried, put through an outdoor conduit that can get water inside it, baked in the sun, or otherwise exposed to the elements.