Neapolitan pizza ovens are basically cement cupolas with stonelike floors. They're traditionally heated, by fires of olive, oak, or beech, to around 700°. If this seems a bit much to ask from your electric wall oven, you're right. You can come close, however.
Make your own "stone" floor with a pizza stone, available in houseware departments, or simply line the bottom rack of your oven with inexpensive unglazed terra-cotta tiles from flooring stores. Before making pizza, preheat your oven, with the stone or tiles in it, for at least 30 minutes.