I’ve gotten so that I am somewhat less interested in great old signs for their own sake (though I am still!) than I am in what signs signify, specifically when that signification is not what was originally intended, but rather the product of age and wear and/or recontextualization. This was not an especially special sign to begin with, but it seems to me just right as a distillation of our mis/disinformation age that it should be rusted and eroding all along the bottom edge, with the rust creeping up toward those trusty and official looking capital white letters. Anyway, that’s how I see it!
11 x 2 9/16”. Looks to me like like enamel paint on tin or aluminum. Stable condition, not shedding with holes in the top corners for hanging.