Motion sensor switch doesn't fit in faceplate
You can't use that kind of faceplate with that kind of device.  (Unless you're willing to hacksaw off the wings, but that will mean it can only be used in this type of faceplate, and will never be mountable elsewhere because you will have destroyed the screw threads that mount the Decora faceplate). 

You need this 


src


You install this cover ("mud ring"). 
Then, you install the Decora outlet (or any device) in the normal way. Those two nubs give you mounting holes in the normal location.  Remember to remove the paper squares if you're grounding via the yoke. 
Then install a common/normal (e.g. Decora) cover plate. 
This works with anything that will bolt into a normal box.
The only downside is the cover plate may overhang a bit, but a careful choice of cover plate will help that. 


Technically these things are called "mud rings", because it's intended that you install the mud ring, then lay drywall over it. They are made in different depths for that purpose.  They also make flat (0 depth) plates, do not use those because the Decora cover plate screws will bottom out if you do. 

The large opening meets the requirement for accessibility without tools.  Wires must stick out at least 3" beyond the surface. 

What it's doing is emulating a common 1-gang "handy-box". Except with a many more cubic inches available to you.  You need the cubes practically for bulky devices like these, and you need the cubes statutorially for box fill.