My Rotary Mower Has Suddenly Started To Trip The Safety Switch.?

It still seems to run OK without going through the security device, but I worry that is triggered when I use a power tool outdoors. Inquiries I did say scrap it and buy again because I could buy a new one for the money to do not even inspect repaired. Advice to date is to remove the top cover and remove all debris and let it dry. If I had not had the help of a safety switch I could still use this machine in ignorance of its potential dangers, if any.