Although it may be news to you that you “have a business” (and most of the other people who get their first 1099-MISC); The IRS considers anything in box 7 of 1099-MISC to be self employment income. Enter the 1099-Misc income, at Other Common income / income from a 1099-MISC . TurboTax (TT) will complete Schedule C or C-EZ for you and allow you to deduct any expenses associated with this income. You'll also have to pay self employment tax (social security & Medicare) on any profits greater than $400. These types of payments are frequently done this way. Your "employer" is not the only one.
The IRS also considers undocumented cash income (no W-2 or 1099-MISC), for work performed, to be self employment income.
Since the IRS considers anything in box 7 of 1099-MISC to be self employment income. TurboTax (TT) aggressively steers you in that direction, even if the amount is in box 3. If you try reporting box 7 income as anything else, you chances of hearing from the IRS are very high.
That said, the key to getting TT to treat it as other income is to follow these steps:
Enter the 1099-Misc
On the next screen Describe what the payment was for
On the next screen select "none of these apply"
On the next screen select "No it didn't involve work like my main job"
On the next screen select "I got it in 2018" ONLY
On the next screen select No, it didn't involve intent to earn money
TT will put the amount on line 21 of form 1040 (Schedule 1) as other income
