Friendly Neighbor or Creepy Neighbor?

Met my neighbor the other week in the elevator as I was leaving for the airport. A middle-aged man also in temp housing. He mentioned getting together for a drink and helping me get oriented to the area (although I thought I was clear that I'm from this area). I said, "Yeah, sure," and went on my way. Yesterday there was a note on my door. Something to the effect of "Rebecca, Feel free to stop by and visit anytime after 7 p.m." I wrote back on the other side of the note that I had plans that night and actually through the rest of the week, which is true. Today there is a new note on my door saying that next Tuesday is fine and that he could "also do the weekend."

So, tell me...is this creepy dirty old man or friendly neighbor? Would you invite a single female to your apartment "after 7 p.m." that day and not include a plan i.e. "knock on my door and we'll go grab a drink," or "come over for dinner," but instead just ask her to show up no other plans mentioned? Wouldn't you include a phone number and say let's make plans or reference going out to a neighborhood bar/restaurant instead of hanging at his apartment?

Am I over-thinking this, or is it weird?