Here's your reply (although you probably won't like it):
Others have this issue with the mail box and I have not found anyone who knows how to delete the extra mail box (this is also a problem if you turn an residental lot into a commercial one. The mail box also gets stuck)
As for the unicorn, the game MIGHT clean that up by itself. It does clean up stuff from time to time but I kinda doubt it recognizes the unicorn as a object that needs deleting so you're probably stuck with it.
I can offer you two solutions
I hit that button by accident, on the mailbox, too, and had the same thing happen with the extra mailbox. I had just shared the house on the gallery right before then. I was re-sharing a prior house that hadn't been decorated for Christmas, so I put the undecorated house back in and redecorated it and reshared it. However, four people had already downloaded it, which floored me. Normally I don't get that many downloads right away. Go figure. ;-)
Anyway...all was solved by reverting to the saved copy, but I sure hope EA fixes this problem!
Actually, the problem is quite simple to solve. I just did it, well, for the mailbox head. Do not restart your game, just click the mailbox on top of your sims head. SHIFT-click and then click "Reset Object (Debug)" and it will automatically come off of your sims head. Then, just simply go into build mode, select it, and delete it. You'll even get money for it. That's how I solved it.
