bad fever

Since I want to work on my letter writing and character building, I think it would be cool if we did it as a fictional thing.  So here's my idea:

The two people corresponding don't know each other, but I address a letter incorrectly and it winds up in your mailbox.  The letter is addressed to a friend that I've not spoken to in quite some time, and so I sent it to their last known address, which is now yours, as the person has since moved or passed away or something.  It is full of information as to how everything in my life is going, and you are intrigued and respond. 

It's up to you as to whether or not you pretend to be this person at first or say outright that he/she/it no longer lives in that place and you got the letter because it's you address now or whatever.  But yeah, anyway, we build a friendship throughout the letters and so on and so forth.

I don't really know where else to go from there, but it seemed kind of interesting to me.