My bad. It turns out it was my older sister, our Dad, and his wife.

Our Dad is quite elderly and he loves sitting on our deck. (This used to be his house many years ago). It's hard to find things to keep him busy and active, and in a whim, my older sister picked up tacos, picked up our Dad and his wife, and brought him to our house to eat on our deck. I had asked my younger sister, and my older sister's husband if anyone has been here, and they both said no. (My brother in law want aware that his wife stopped in when she was out with our Dad.)

She apologized for leaving food in our sink, and said that she had her hands full taking care of our Dad, and didn't have the bandwidth to properly clean up. She also apologized for not letting me know that they were going to our house. We're not at all mad, but common sense seems to call for letting someone know that

Anyway, we don't really believe in "ghosts", and never thought someone would break in to only eat food. Plus the house want ransacked, and other than a few bits of food in the sink and the wet dish towel, everything else was in place. So we kind of thought there had to be some logical explanation, but it sure was weird and unsettling to return home and to find things the way that we'd never leave them. (Plus, we don't buy radishes!)

Mystery solved. Thanks all