You are geeting alot of mixed information. If you are on SSD winning a sweepstakes is NOT considered earned income, and will NOT effect your monthly income.. However, if your total income goes beyond $25,000 for the year, you do have to file tax returns and claim the income. But it will not effect your social security income as it is not earned income.
Now, if you are receiving SSI Disability (those who do not have enough credits with SS to receive SSD) then if WILL effect your Social Security monthly benefits.
Which ever you receive, if you have an income of $25,000 or more for the year, you must file a tax return. It your total income is NOT over $25,000, you do not have to file a return. But you may have to pay taxes on the winning amount. This you should speak to your tax person. I do know that if your Social Security Disability is less than $25,000, a year you do not have to file a tax return.