A lot of the newer houses are starting to use the Decora style of cover. I often get asked if I am able to accommodate the light switch covers with the larger rectangle opening. They are often called Rocker switch plates or Dimmer switch plates as well. You might also use these covers for electrical outlets that feature a GFI or GFCI switch. Most of my patterns are available for the Decora style of light switch covers. They are available in Single, Double, Triple and Quad width. For ease of ordering on Etsy I refer to them as D1, D2, D3 & D4. All of the examples in this first picture use the D1 cover. Because of the larger opening not all patterns in my shop are available for the Decora style, but there are still plenty to choose from!
Here are several examples from my Rocker / Dimmer / Decora Pinterest Board