Any Idea What This Is?

Thanks in advance!

Let's be complete about the origin of this query, shall we? In an email message to members today, among other things, Mike J Y Roberts FRPSL, President of The Royal Philatelic Society London, posted the same image and asked members:

cjpalermo
Thanks for the additional background information. The geographic area of where this was discovered may be an important clue (as well as giving proper credit to the query)..
Alas, it would also be helpful to have some idea of size, and the simple design and quality give the first impression of being very small, like something from a child's toy post office game.

You beat me to it, CJ.

I think a toy post office would have better stamps. Along those lines I would suggest a child with access to a sewing machine, a printing set and either stamps made from potatoes or a steady hand might have made a "stamp". When I was small I remember being fascinated by the ability of an empty sewing machine to perforate paper. Though my mum got mad if she caught me turning the crank handle of her sewing machine.

My best guess would be a label issued by a socialist party in Central Europe, i.e. proof of having paid a membership fee. The building looks like something from that region. PS could be 'party socialist' in some languages. That would make me think of Romania.

Another possibility that comes to mind is a rationing coupon.