I found this alongside our house. The nearest patch of milkweed is a good 20 feet away. It seems after they've reached the last instar, adult caterpillars will abandon the host plant and make their chrysalis elsewhere. A few of course do stay on the plant but I've found this to be uncommon, (though not rare).
It hangs here like a fine piece of jewelry.
Note the wonderful shade of green accented by the black and gold trim.
A ring of gold spots circles the bottom. I can't help but think their function is only to look beautiful.