1989 300e parasitic power drain
 

After one relatively small problem followed by another, I have now developed a battery drain. The dome light switch is where my suspicion lies. Every thing was fine then one day the fasten seat belt light remained lit and blinking and the light switch quit functioning. This is an indication of a faulty switch? Then after several months, the fasten seat belt light quit lighting. Now the battery drains. What are the odds of this being the culprit or something deeper? I'm not certain how to test the switch as well as the wire feed.