I hired a cabinet maker who then installed out kitchen cabinets and mentioned to me that he can feel air blowing through the lightswitch while the kitchen fan was on. He can't speak English well so I can't tell what the reason why it was bad. He said something about a getting gasket or a foam spray to block the air from blowing out but I'm not sure what it's about. Can anyone tell why it would be bad? Does he mean it wasn't installed correctly or is it dangerous?