The negative amount does not get entered as a 1099 MISC. From the self-employment entry screen you would select to enter Other Self-Employment Income and then enter the negative amount on that screen along with an explanation (enter the minus sign before the number). See the sample screenshots below.
To be brought to the self-employed income section in TurboTax, take the following steps:
Type Schedule C in the Search box and then select the Jump to link. You may first be asked some general questions about your business. After you answer them, you’ll be taken to the Let's enter the income for (your line of work) screen where you can enter this income as Other self-employed Income.
Thank you for your response. However once I entered the negative income ($-10,000) my federal tax refund dropped and my income and adjustments increased. I thought it should be the other way around. I tried putting a positive number ($10,000) and my refund increased but the taxable income increased. This does not seem right to me.