I've seen the item Susan posted for HO as well, but not O.
I think Matt has the answer. Make 'em.
I've been toying with the idea to flank my switches with something similar. For no apparent reason I occasionally get a derail on a light car, they would be re-railed automatically with the right pieces added. It would save the breaker popping and me having to crawl under to reach them. My knees don't like the crawling any more.