I planned to do the same job for my garage door opener using wire cover and add a receptacle on the surface of ceiling. http://www.homedepot.com/s/wire%2520cover?NCNI-5. If your light is a recess light, or you need a better looking ceiling, guess you have to do a real job, cut drywall, drill holes to add a new receptacle box. I saw people did it. Don't put projector too close to light, heat may damage it.