I just fixed mine the other day! I took the little slider switch off (it in the door jam) and the contacts were a little corroded like a battery terminal. I order to get the part out I...
1. unscrew the assembly with one phillips head screwdriver
2. unplug the connection after you pull out the switch
3. pull appart the slider switch, be careful not to lose the spring!
4.Clean the brass contacts with fine sandpaper or scotch brite.
5. reassemble in reverse order and let there be light!