Problem with Light

Basically I have a lantern that my player holds. I've illuminated the lantern by adding a point light right inside the lantern. Only problem is when i walk up to a wall the light goes through the wall. I fixed the problem of the lantern going through the wall with a camera trick where you duplicated the camera. (more info -> http://www.youtube.com/watch?v=bBrr-esgV8E&feature=channel_video_title) Is there something like that or another way I can fix my light problem?