One similar to the one on this forum which I pasted below.
RE: [insert account number or name of account or name of debt]:
Dear [insert collector's name or company name],
This letter is in response to your [letter dated xx-xx-2005] (copy enclosed) or [phone call on xx-xx-2005], concerning the collection of the above referenced [account or date].
I do not believe I owe what you say I owe therefore I dispute this debt. I am well aware of my rights under the Fair Debt Collection Practices Act (FDCPA) and my state laws so I hope to save both of us a great deal of time by letting you know that not only do I dispute the validity of this debt, I have also checked with my State Attorney General and verified that the Statute of Limitations for enforcing this type of debt through the courts in (insert your state or the state in which the contract was signed) has expired. Therefore, should you decide to pursue this matter in court I intend to inform the court of my dispute of this debt and that the "statute of limitations" has expired.
This letter is your formal notification that I consider this matter closed and demand that you, or anyone affiliated with your company, stop contacting me regarding this or any other matter except to advise me that your debt collection efforts are being terminated or that you or the creditor are taking specific actions allowed by the FDCPA or my state laws.
Be advised that I consider any contact not in accordance with the Fair Debt Collection Practices Act a serious violation of the law and will immediately report any violations to my State Attorney General, to the Federal Trade Commission and, if necessary, take whatever legal action is necessary to protect myself. Be advised that I tape record all phone calls and violations of the FDCPA can result in you or your company being personally fined up to $1,000 per incident.
(Sign above name)