CANTEX 1-Gang PVC New Work Switch/Outlet Electrical Box (24-Pack) in the Electrical Boxes department at Lowes.com
ARLINGTO Arlington FA101 1-Gang Adjustable Non-Metallic Outlet Box 3.720 Inch x 2.299 Inch x 3.875 Inch 21 Cubic-Inch in/Out Box : Amazon.ca: Tools & Home Improvement
Carlon Adjustable Box 21.0 Cu In Pvc 1 Gang Bx, Outlet Boxes - Amazon Canada