Here's the bad news. To be in business finding lost items, in nearly all states (including Texas) you must be licensed as a private investigator. Pretty much anyone in the business of treasure hunting for a fee for others would fall under these laws. (Only six states don't require PIs to be licensed.)
I think these idiotic laws were in response to people used public records to locate people's unclaimed balances from businesses, utility company deposits, banks, etc., and then they'd offer to split the money with the rightful owner.
A licensed PI who sees your card, advertising or hears about you probably wouldn't hesitate to protect his or her turf by reporting you to the state. Anyone else could also report you.
Texas law is as follows:
Sec. 1702.104. INVESTIGATIONS COMPANY.
(a) A person acts as an investigations company for the purposes of this chapter if the person:
(1) engages in the business of obtaining or furnishing, or accepts employment to obtain or furnish, information related to:
(A) crime or wrongs done or threatened against a state or the United States;
(B) the identity, habits, business, occupation, knowledge, efficiency, loyalty, movement, location, affiliations, associations, transactions, acts, reputation, or character of a person;
(C) the location, disposition, or recovery of lost or stolen property; or
(D) the cause or responsibility for a fire, libel, loss, accident, damage, or injury to a person or to property;
(2) engages in the business of securing, or accepts employment to secure, evidence for use before a court, board, officer, or investigating committee;
(3) engages in the business of securing, or accepts employment to secure, the electronic tracking of the location of an individual or motor vehicle other than for criminal justice purposes by or on behalf of a governmental entity; or
(4) engages in the business of protecting, or accepts employment to protect, an individual from bodily harm through the use of a personal protection officer.
(b) For purposes of Subsection (a)(1), obtaining or furnishing information includes information obtained or furnished through the review and analysis of, and the investigation into the content of, computer-based data not available to the public.
Acts 1999, 76th Leg., ch. 388, Sec. 1, eff. Sept. 1, 1999.
Amended by: Acts 2007, 80th Leg., R.S., Ch. 906, Sec. 4, eff. September 1, 2007.