Just called my DH, who works in the electrical supply industry to see if his company stocks these. They do. Of course, he kept refering to dimming the Ott lamp and it took a minute for him to understand my desired use. (He thinks in a very linear fashion - a light dimmer would only be used for dimming a light, right?)
When he 'got' it, he said, "Where'd you hear that nifty little tip?" Well, the Quilting Board, of course. Fabulous idea!