If this is a one-time favor and the taxpayer is not engaged in an going trade or business as a handyman, I would consider this as "other income" and not self-employment. You report in the other uncommon income section. You don't pay the additional self-employment tax, but you can't deduct work-related expenses.
For tax purposes, the IRS doesn't care if you have or don't have any kind of state license that might be required. what the IRS wants to know is, are you engaged in a trade or business. If so, it is self-employment income. If not, you are probably safe treating it as "other income" as long as you don't start reporting similar income or doing more jobs for people.
