I'm in the process of changing a burned out bulb in my Amerlite #400BC (120v) light assembly. I have pulled the light out of the housing and disassembled and cleaned it. I plan on replacing the gasket, but I have a couple of questions. The lamp looks just like any outdoor floodlamp, but I see online that the vendors are asking $30 to $40 for replacement lamps. Is the proper lamp something special? Also I'm have a hard time believing that assembly won't leak water into it over time. Is there some caulk or something that I should be using on the gasket?