The census enumerators were only human and often made mistakes. Our ancestors also share in the blame. After all, the enumerator could only record what they were told by the person they were interviewing. In this case, however, the combination of data across three columns at first look seems okay, but after a moment of thought just did not seem correct.
1920 U.S. census record for Ike Shelton
The 1920 census instructions defines own account as
A person who has a gainful occupation and is neither an employer nor a salary or wage worker... Such persons are the independent workers. They neither pay nor receive salaries or regular wages. Examples of this class are: Farmers and the owners of small establishments who do not employ helpers...In contrast, an employer is defined as
...one employing persons...in transacting his own business. The term employer does not include the superintendent, agent, manager, or other person employed to manage an establishment or business...With this distinction in mind, I realized that Ike Shelton likely owned and ran his own small business. He was his own boss and employee.
As genealogists, we spend hours examining the population and non-population schedules of the census for our ancestors. We faithfully record the who and when and how old, and maybe make note of occupations and other items of interest. Attempting to understand the reasoning behind the responses recorded by the enumerator, by reading the instructions for each census, helps to make the information gleaned that much richer.