Daewoo cog 370a

Question

the light is out in this microwave.I took off the panel off on the inside right wall. Can't find anything in there. I turned it upside down and unplugged it. There was a s***w in the bottom where there is a grill. I unscrewed it and pushed on the plastic tab in the grill. I thought it would open. I didn't. Now the s***w won't go back in because whatever it screwed into is not there. and of course, the plastic tab won't come out.My question is what did I do by taking out the s***w and pushing in the tab. Is it safe to use?I guess I'll just forget about replacing the light unless you have any suggestions.MA