Antique/vintage enamel convex sign or wall plaque - skull and crossbones with red lightning strike superimposed on top

Antique/vintage enamel convex sign or wall plaque - skull and crossbones with red lightning strike superimposed on top. Polish, circa 1950s. An electrical warning in Polish. It has 4 holes to screw to wall; convex in shape, ie not flat. Size: 24.5 x 15 cm. Weight: 350g (allow up to 1 kg once packed). Various superficial marks & scratches and some discolouration and corrosion but all part of its industrial charm and character. Priced accordingly.