Employee security awareness development. Vulnerability testing and security audits. General security resource assistance. Do not hire someone who only checks rooms and phones. This is like locking only one door in the building.
Information theft occurs in many ways.
When interviewing potential consultants be sure to ask for a detailed resume, and check it for accuracy. Counterespionage will not be supplementary to some other income source. A license and bond is required in most states. The type of instrumentation used. Proof of insurance.