The answer is very simple. Recycle them!

If at all possible, contact the campaign manager of your issue or candidate to see if they want them back. Reusing them is always better than recycling because less new material needs to go into the campaign process.
If the folks representing the issue or candidate do not want their signs back, simply take your sign off the post and take it to your nearest recycle depot. Each transfer station has a recycle depot and is ready to accept all your plastic waste. I am certain you will find plenty of uses for the wooden stake. I think the vampires will be staying clear of Douglas County for quite some time now.
