If he is still a member of the church (or even if he isn't they would have the last known address.):
How to find members through the Church Call the Member and Statistical Records Division at the church office building. The phone number is (801) 240-3500. If you're not in the USA, or if you'd rather do things in writing, the postal address is:
Member and Statistical Records Division The Church of Jesus Christ of Latter-day Saints 50 East North Temple Salt Lake City, UT 84109 USA
??Request a copy of their Membership Contact Form. They will mail it to you promptly. ??Fill out the form, which asks for information about the person's name, age, birthplace, and other facts that might be helpful in locating the one you are trying to each. You will also need to make a brief statement about why you want to contact this person. ??Return both copies of this form to the address given at the top of the form. One of the copies of this form will be sent to the person you are trying to locate, who will then decide whether or not to contact you. If the person cannot be located, the office will notify you of that.
(In the past, this division would forward letters that were sent to them. Currently, though, it is considered too risky to forward an unopened letter to anyone.) http://www.mission.net/en/main_memberlocator.htmlhttp://www.mission.net/en/main_memberlocator.html