I looked up the number on the Internet and found that Kate apparently uses a Sprint-service cell phone in Richmond, Virginia. So last night, with Nomi's permission, I called her up to tell her about the bill.
"Hi, is this Kate?"
"My name is Michael; I'm calling from the Boston area. My wife found your name and phone number on a dollar bill she got in change, and we were wondering what it was about."
"Could you repeat that?"
(more mumbling; but I get the idea that a friend wrote her number down on the bill against her wishes)
"Would you like me to cross out your number?"
(firmly) "Yes. Please."
"Will do. So you won't have to worry about anyone calling you again." (I suddenly realize how that sounds.) "I mean...you know what I mean. Have a nice life."
Kate of Richmond, Virginia, if you're out there, we've crossed out your name and number in black Sharpie pen.