A vintage double sided Examination warning sign. 
Originally would have been pinned to the door to the room, to warn people of the upcoming Exam. Then when the examination is taking place it would have been flipped over to ask for silence in the vicinity of the room! 
Now the question is. . . is this from a school or a hospital/doctors, begging the question, what kind of Examination? 
Measurements: 38 x 30cm