Unfortunately, campaign signs are tough to recycle. Those made of plastic sheeting are akin to single-use plastic bags and do NOT belong in the recycling bin. You may be able to take them to grocery stores that recycle bags.
Metal brackets are considered scrap metal and also do NOT belong in the recycling bin. You can take them to a scrap metal dealer, such as Accurate Metals, in Lansdowne. Another option: reuse the brackets as supports in the garden.
photo by Susan O'Donnell