After doing some searching here I found that I was not the only one with this issue. My microwave oven began to stay on or the blower stayed on when I opened the door. This lasted a couple of weeks and then it just stoped working altogether. I found this site and saw I was not the only one with this issue. I ordered two different kinds of door switches recommended here and found a utube video on how to remove the unit from the wall. A note of caution , the parts you have to remove to get to the switches are mostly made of plastic. I broke a couple of screw attachments by not paying close enough attention to the utube video. I was fortunate that none of these broken plastic pieces caused any issues when putting everything back together.
Bottom line was the switches were the issue and I am very pleased. A $20 part instead of a $200 minimum repair bill!