I have never seen an envelope stuffing job that isn't a scam. Stay far away from them! If you have a computer, and depending on your skills and experience, you can find employment that allows you to work from your home.
1. You can do freelance writing jobs, these consist of writing articles, blog, content, web content, ghost writing, techical writing. Most of these jobs are freelace basis and plenty of jobs are available around.
2. You can make your own website/blog and earn from google adsense. It will take some time and hard work, but rewards are great and long lasting.
3. You can do transcription job from home.
4. You can earn money from completing projects available on online marketplace like guru.com or getafreelancer.com
5. Proofreding and editing written content
The best place to start looking for positions is http://www.workathomedesk.com - it has a large list of legitimate companies in the work at home directory section.
Good luck!