97 Altima GXE Brake Light Problem 120k miles

[scubahoops]

Recently I noticed that the right brake light is not very bright any more. I thought it was the bulb, I replaced that and tried good lights and that is not it. It is very dim, but you can see it. The turn signal works fine as do the parking lights. I looked through one of the repair manuals and I think it could be either the brake relay or a short, but I am not sure. If that is it, I would like to replace the relay, but the manual does not say where that is located. I am hoping that someone can help me out with this.