What are plastic electrical boxes?
Plastic electrical boxes have their pluses and minuses. Because they are plastic, there is no need to attach a ground wire to it. Since it is made of a non-conductive material, switches and outlets cannot short out if they touch the side of the box.
Plastic boxes usually come with tapped screw holes for easy attachment of switches and outlets. These boxes come in a single-gang, double-gang, and even multiple-gang configurations.
You can choose between plastic boxes with nail-on brackets, complete with nails, or a cut-in version that has tabs that spin out when tightened to hold the box securely to the wall.
The disadvantages of plastic boxes are their brittleness and wire support brackets. Let me explain. If you look at the box, you'll notice that the device screw holes are also plastic. If the screw is lined up when installing the device, you're fine. But get the screw cross-threaded and you have a problem.