One of the funniest practical jokes I have ever played came from this exact same situation:
A parent from our children's school was running for some local office. My bff and I were not very fond of him but always smiled and made nice because it was the right thing to do. When he announced his campaign we both

and of course he assumed we would all be voting for him. So she comes home one day to find his campaign sign in her yard-- It was a bright orange sucker and she was mad!!!
Of course the first thing she did was call me and I could not stop

about it. We had no idea who put it in her yard and I had to tease her about it. She pulled it out of the yard and I thought that was the end of it. Until about a week later I look out my window and there is one of his ugly orange signs in MY yard!!! Of course I immediately call her and she tried to play it off but she couldn't keep from laughing-- she and her husband had driven by and put it in my yard as a joke. So the sign went into my garage, to wait for the perfect revenge.
Fast forward about a year and she is moving away.

DH and I KNEW that this sign had to end up at her new house 6 hours away somehow. I was in constant contact with her the day of the move and she had to leave and pick up some things, leaving the movers by themselves at her house. MY OPPORTUNITY! I grabbed the sign, jumped in the car and raced to her house. I gave the movers some $$$ and told them the story and begged them to please hide the sign in the truck and then quietly put it in her yard when they had a chance while they were unpacking. (it was the same crew loading and unloading)
Then I just had to wait.......
3 days later my phone rings around 10 am and when I picked it up she was


so hard she couldn't even talk!! Which of course set me off. Never ever would she have thought she would walk out of her house there and see that sign in her yard!
Even now, 8 years later, we laugh about it. And frankly I worry that the sign may still be in her basement, waiting for the perfect opportunity for paybacks!