If that's your only income (self-employment), you have to file a return if your net income is over $400. You will pay self-employment tax (the equivalent of Social Security and Medicare) once your net income exceeds just $400.
Its similar to when you work as an employee and get a W2. They take out Social Security and Medicare on next to nothing. Same idea here.
If you have other income, then the threshold would probably be $0 and up. If just the cleaning is over the $400, you would owe tax no matter what else.