You can earn money stuffing envelopes but you have to get other people to signup for the envelope stuffing program in order for you to earn your money.
You signup for the envelope stuffing company, the envelope stuffing company then sends you a flyer which you make copies of and then you then stuff envelopes with those flyers and mail them to people on a mailing list and hope they signup for the envelope stuffing program.
If those people signup for the envelope stuffing program then you earn a small commission of around $5.00 but you must first pay a fee of around $35.00 to $75.00 to get started with the envelope stuffing program.