Instructions
Go to the Neighborhood screen. Type in "boolprop testingcheatsenabled true" without the quotes. If this code doesn't work, type it in again, but this time reading: "boolprop .testingcheatsenabled. true"
Go to the create a family screen. Hold down the Shift key and press N.
Check the outfits and skins now available. You will have all of the non-player character outfits and a variety of skins, based on which expansion of the Sims you have and how many additional files are available.