1984 electrical problem

[megadeth8318]

I recently started having problesm with my dome light in my 1984 lesabre. When the doors are shut and the switch is off, the light stays on. I checked the switch, and it seems to be wired properly. I also checked the door switches, and they are working properly as well. Does anyone know what might cause the light to stay on all the time?

[maxwedge]

dash dimmer switch turned all the way may cause this.

[jonsonton]

How do you know the door switched are working? Also the dimmer switch might be sticking.