Hello. I recently came across this laser system that you can use your own pistol with a laser in the chamber and shoot at a box with receptors on it thus allowing you to practice at home.
Below is the attachment of this system:
I own a laserlyte and it is great for practicing trigger control or unholstering. The only real downfall is most pistols will only fire once unless you manually work the slide. Most you only need to move the slide slightly but without an auto reset you cannot practice drawing and firing more than one round.
If you want to fine tune your trigger finger it is great. If you want something to practice defensive shooting a SIRT pistol would be the way to go. They only come in the GLOCK variety at the moment but an M&P version is supposed to be out...well 2 years ago...