"Your interview is slated to appear on tonight’s evening news, Mrs. Shelton."
The comma is placed after "evening news" and before "Mrs. Shelton" to separate the name and address the person being referred to directly. This makes it clear that "Mrs. Shelton" is the one who is the subject of the sentence, rather than just a part of the news broadcast itself. The comma helps to indicate a pause and makes the sentence easier to read and understand.