A few options:
To run any wires into it, just drill a hole, run the wire, and silicone it up.
The heat alone of your fermentation might be enough...you'd need to run a test fermentation to know for sure. In fact, it might be too much! In this case, you could make kind of a reverse "son of a fermentation chamber", and have a fan to exhaust hot air and pull in cool air, (run the fan off of the temp controller).
If you are sure that it's always going to be too cold, I'd build a chamber with a heat source and a fan, and a dual temp controller, (I love the ebay one...$30 and it can do both heating and cooling). Hook the fan up to the cooling circuit, and the heat source up to the heating circuit. Then you are sure to stick within your range.
Also, light bulbs are iffy....they produce lots of heat, but they also put out light that you have to shield your beer from, (that much light, that close, could skunk the hops...incandescents still put out a BIT of UV, (though very little....it' PROBABLY isn't a concern)). Still, if it were me, I'd use a heating pad, (like what you use when you have a sore back), instead of a light bulb.