They won't say what their business is if they haven't called for you (who answered the phone). They simply say "it's a personal business matter" and will not leave a message.
I found this though: Cap Research Institute Inc.
14420 W Sylvanfield Dr
Houston, TX 77014
I believe they are actually doing business as Amidee Capitol LLC, www.amidee.com, 14420 W Sylvanfield Dr # 100, Houston , TX 77014 - 1625. They claim to be a Real Estate investment firm, but why all the secrecy? 281-315-2100.