It was shocking, if not surreal. The email message was from a woman I’d never met and whose name I recognized only because, a few months earlier, she mailed me a book she’d written. The message announced that she and her family were planning a road trip to Disneyland and would just love to stay with us since (at the time) we lived nearby and oh, wouldn’t that be so much fun. She gave a tentative date they would be arriving. Everything I know about what not to do as a house guest, I learned from that experience, from the moment they drove up (cue music for Cousin Eddie and family from “National Lampoon’s Christmas Vacation”) to the time they finally departed. Full disclosure, because I have friends and relatives who read this column, be it known that all our other houseguests have been wonderful. Exemplary. Do not worry. This …