I found one of these once, or was I given it? I can’t remember. Anyway it’s a small piece of paper with writing on. It reads…
“I am an alien life form with the appearance of a small piece of paper.
I communicate using black lettering. Right now I am having sex with your thumb.
I like sex, so when I’m done, if you’ll put me on the floor for someone else to find that would be great”
I went ‘euugh’ and dropped it. Apparently most people do. I just made one for my workmates to find.
Oh I so have to do this.
::scribbles on paper::
I’ll report back.
After you read it did you sniff your fingers?
The one I saw also had some words about you enjoying it or smiling right now. It didn’t mention being on the floor- just suggest that you pass it on to someone else.
It was circulated throughout my 10th grade English class. I don’t know that the teacher ever noticed it, but most of the rest of the class did.
Hahahaha, this sounds hilarious. Too bad I’m done my (informal) schooling or I suspect there would be a lot of close encounters.
Oh! I remember that from high school, yesssss. Though I don’t remember the circumstances. We all found it hilarious.
Bwah ha ha! I started a variant of this in sixth grade, but some weaselly little girl passed it up to the teacher, who immediately recognized my handwriting and threw me out of class.
Weiiiiiiird. I’ve got to try this. 
I’ve seen the e-mail one, where thumb is changed to eyes.
As in:
“I am an alien life form who has connected to your computer.”
I communicate using a visual medium. Right now I am having sex with your eyes.
I like sex, so when I’m done, if you’ll send me on to someone else that would be great"
or something like that.