This has happened to mine several times. The switch is in the sill, a little white plunger. Unscrew, pull it off the sill and clean it, put it back and hopefully off you go. I suspect you can buy new ones from one of the usual suspects.
Al Look at the bottom of the door you will find the s/w Some knead the plastic/rubber spacer ( mine doesn't ) to finish the travel if that's not it st sw or connection If it's the s/w don't buy the norm you need the 2 wire ones