Source: Ballot Access News
On April 30, the three candidates on the ballot for U.S. House, South Carolina First District, debated each other. However, the debate was not televised. It was sponsored by the NAACP of Goose Creek, and was held the evening of April 30. No news article have been found that describes the debate, but here is a story saying it would take place. Thanks to Michael for the link.
Click here to read Ballot Access News comments on this article