If you are sure you sent it to the incorrect address then you can re mail a copy. If they forwarded your return then the first to be filed will be accepted and the second one ignored. Pick your state for the address needed ... https://www.irs.gov/uac/where-to-file-paper-tax-returns-with-or-without-a-payment
How long ago? It takes about 3 weeks before an amended return shows up on the IRS web site and you can probably add a week or two for it to get forwarded to the proper place.
You can check the status of your mailed amended return at this link but allow 3 weeks after mailing before checking.
<a rel="nofollow" target="_blank" href="http://www.irs.gov/Filing/Individuals/Amended-Returns-%28Form-1040-X%29/Wheres-My-Amended-Return-1">http://www.irs.gov/Filing/Individuals/Amended-Returns-%28Form-1040-X%29/Wheres-My-Amended-Return-1</a>
However, if you send a 2nd copy, and the 1st one does get entered in addition, that will probably extend the already slow 16 weeks (4 months) to process an amended return considerably since they will have to have a human review both to resolve the two and that takes time.
If you do send a 2nd amended return be sure to write in big letters that this is a copy of an amended return already mailed to the wrong address at the top.