Can a schizophrenic earn a little extra cash without losing benefits?

I'm paranoid schizophrenic and want to spend about a half hour a month buying and selling products on the internet.

I grew up in government institutions and when I became a adult worked for a awhile (while I was still ill but I got even more ill as a result) I got back on ssdi. I have decided that work is unhealthy for me and do not want to return. I see a doctor and take medication daily.

But I would like to earn some extra cash so I can get a apartment. Can I earn money without losing my benefits? How much? Will it cause me to get reviewed. Will I lose my benefits?

Thanks for the advice. It was very nice of you to answer my post.