Errr...Help!

I just checked my mobile and found a text message on it from 14:30:

Did you get my text hun ? Im waitin for you at yours but need to get back before four ! X

I'll resist criticising the woeful spelling and punctuation and concentrate on the message itself.  I don't know who it's from, the number isn't in my phone and I don't recognise it.  This means that the person possibly sent the text to the wrong number.  The sender seems unsure as to whether I have received a prior text (I haven't) so it's possible that the sender is a serial wrong-numberer.

The sender is, according to the text, in my house.  I have scoured the house.  There are no additional strange people here.  Again, this points to a wrong number.

The texter addresses me as "hun" - I assume that this is an abbreviation of honey, not a war-film related pet-name - and ends the message with a kiss (a capital one).  From this, I can only deduce that the sender is a woman.

The general tone of the text is both intriguing and revealing; the woman is, according to her, waiting at mine, but needs to hurry away within an hour and a half.  This screams extramarital assignation, which is odd, as I'm not involved in any illicit dalliances.

There are two possible conclusions that can be drawn here.  Either this is a wrong number, or I'm having an affair that I'm not aware of.

I'm not sure what to do now.  Should I ignore the message?  Should I reply?  If I send a reply, what should it be?  Please advise me via the comments section.  I will act upon the best advice.