I was inadvertently copied on one of their letters by a relative. She uses her maiden name initials as her name and uses a PO box as her address. It took me a while to determine who this person was in the letter. The letter itself was a weird witnessing with lots of scriptures. Ends with how the world is ending and they have a chance to live forever on Paradise Earth! See your dead relatives!
I actually got, in my regular mailbox, a similar letter from some whacko. No name, no religion referenced. Just weird ramblings about God, etc. Threw it in the garbage.
The relative tells me, every time I call her, about her "Witnessing by letter" and how effective it is and how many new JWs there are as a result. I grunt and say "Yes, I'm sure.." as I put the phone on mute and laugh!