Sideways flip horizontal toggle switch plates were commonly installed in homes in the 1970's and 1980's. They use a duplex opening, which are also used to cover a duplex outlet. Available in a variety of finishes, all UL listed and made in America.
IMPORTANT! What You Should Know About Horizontal Toggle Switch Plates:
Sideways toggle switches fit the exact same switch plate as a duplex outlet.
Remove your old switch plate from the wall and look at the base of your horizontal toggle switches. The shape of the base should be identical to a duplex outlet.
The Difference Between Horizontal Toggles and Despard Toggle Switches:
If you have Despard Toggle Switches, which are smaller than horizontal toggles, you'll see that they are mounted in a bracket and the screw holes for the switch plate are at the top and bottom of the bracket. You will need a despard wall plate.
IMPORTANT! The Switch Plates below are duplex switch plates shown with horizontal toggle switches. The switches are not included.
Note the size of your switches. The base of a horizontal toggle light switch is large enough to fill a duplex outlet cover as shown above and below (more than 1" across). And while both types flip east to west sideways, the Despard switches look similar but are much smaller, with a base that's under 1".