A similar question to yours was recently answered here on this forum, and I believe that the same solution will work for you as well.
Yes, the income you received from being an "election judge" is considered taxable income by the IRS, but it's not quite the same thing as true self-employment income. Thus, it is taxed somewhat differently (specifically, it is not subject to Social Security and Medicare taxes).
Please follow the discussion, and the data input instructions, provided at the following link:
https://ttlc.intuit.com/questions/3771859
Although that other answer was written for a taxpayer in Tennessee, and for a $50 amount, please just use the same general process, but instead substitute your actual amount received for the $50 figure input there. Also, you will want to type in the name of your own home state, assuming that it is not Tennessee.
Thank you for your inquiry.