(Washington, D.C.) -- Oregon Senator Ron Wyden has conducted a "secret shopper" study of health insurance companies finding so-called ghost networks. That's when insurers sign up clients, but getting an appointment to see a doctor is very difficult, or doesn't happen at all. They were only able to make appointments 18-percent of the time. A third of the phone numbers didn't work. In one case, a phone number went to a high school student health center. Wyden is chair of the Senate Finance Committee and is working on legislation to address ghost networks in Medicare.