Hex signs have come to be used by non-Pennsylvania Dutch persons as talismans for folk magic rather than as items of decoration. The Pennsylvania Dutch barn hex designs originate with the Alpine Germans. Hexes are of pre-Christian Germanic origin; for instance, a circled rosette is called the Sun of the Alps in Padania. Based on this history, Neopagans or Germanic heathens have taken up the practice of creating hex signs, incorporating other pre-Christian signs and symbols into the hex work. Gandee, in his book Strange Experience, Autobiography of a Hexenmeister, described hex signs as "painted prayers".
These round seals were a tradition carried to the East Coast by Germanic immigrants several hundred years ago. Their formulas were shared in farming communities and repeated with individual variations for a variety of purposes. Some were hung on barns to protect the building from fire, storms and disease, others were intended for the home to anchor peace, fertility and to attract prosperity. Many who practiced this folk art form did not and would not call it folk magic, but if you think of magic as a way of setting intentions to materialize on the material plane, you could easily make the argument that a Hex Sign qualifies.