What's the purpose for the device? I dont know of a company that makes one, but it wouldn't be too hard to do. Just need a U that would fit around the switch with a servo motor attached to it. Why do you need it battery powered though if it is already next to a light switch which will have power run to it. Would save you from having to replace the battery.
I'm not sure if you're application is making it possible for someone who can't get to the light switch turn on the light, you could buy something like this for a lamp in the room...
http://www.thinkgeek.com/homeoffice/lights/bb52/
Or go back to the clapper.
I'm not sure if you're application is making it possible for someone who can't get to the light switch turn on the light, you could buy something like this for a lamp in the room...
http://www.thinkgeek.com/homeoffice/lights/bb52/
Or go back to the clapper.