How do you set effective boundaries with a creep?

Someone did a favor for me yesterday, no biggie really, but then he said just randomly asked me if I knew someone who gave massages. WTH AND WTFF? This guy is married, I didn't put out signals and I was just ok - I am thankful, you're a neighbor and adios and then he just puts that out there. I replied that there was a guy in the neighborhood - why am I even discussing this with him? I don't even know him, he just did a favor and now I'm getting every weird vibe. And THEN he says - no someone gentle. Cringe and barf. So I said no, closed the door - and gathered the pieces of my crumbled self and forgot about it.

Today he messages me (!) on the community group - how I initiated asking him for help yesterday. *Does it work?* I deleted the message. Now slightly concerned. This is exactly what I was talking about here yesterday, these elements that find their way to me as if I have a sign saying open for your craziness. Now how do I put a stop to this insanity before it escalates?