My friend, Kate Erstein, is good. Just when I vowed to stop giving my time away and start doing things only for pay, she convinced me to help her with a volunteer project. She made it sound so simple: help research the history of five historic homes which will be featured in the Upper Arlington Home and Garden Tour next June. In exchange I’ll have a chance to promote my business, Circle of Life Publishing. She dangled an ad-in-the-program carrot in front of me. It really didn’t take much carrot-dangling though because the truth is I love a history mystery. And the tour benefits the Upper Arlington Historical Society. And I get to work with Kate and also Sue Minor, a dynamo and fellow history enthusiast. I said yes to Kate after about, oh, three seconds. So check back to see what we’ve uncovered. First on the list: a Cambridge Boulevard home built by the Miller family in 1916…