Dear Stamp Community Family
Here I have some kind of a propaganda vignette.

The inscription means "Beware, open your eyes! In poor visibility and at night, watch out for danger twice!" This was the slogan for the fight against accidents of the German Reichspost and the German Reichsbahn.
I found a corresponding postcard on the internet. It seems the inscription on the signal board has been forgotten for the vignette.

Does anyone know when this vignette was issued?
Thanks for any hint.
Best regards from Switzerland
André