To answer your original question, your corn does not "need" a light, nor does it "need" a UTH. What is needs is a proper thermal gradient. The exact details of how you reach those temperatures are less important, however usually a t-stat or at least a rheostat (dimmer) are required to properly regulate the heat source.

The person who told you you need a light may have believed that corn snakes need UV light. Corns do not, although some reptiles do, mostly lizards I believe, so that is why some people get confused.

I would be more concerned about making sure your tank is absolutely escape proof, and doing it ASAP.

I also agree with the person who said not to use tape in the enclosure.