I had to go look....I just found my "other messages" , I had a whole bunch in there ~ some of them had to do with groups I like, I never noticed it before, I had a few hits too, asking for a date, one seems to know who I am, but I don't know them, asking if I remember them.
Just ignore it, I wouldn't get all worked up over it. It's just an unfortunate way for some to go around & make random irritants of themselves -to complete strangers. Means little, I'd just delete it and forget it...then move on to your Privacy settings & control more.