[faoileag]

This is possible, at least from hearsay.

1. A decade or two ago a story made the news that some guy was working from some remote place in Scotland, basically in the middle of nowhere, with just a modem and some novel idea: do freelance research in subscription-only databases. Basically just getting accounts for various costly services, then advertise that for a fee you will do research in these services for people who shun / can't afford the costly access. Unfortunately, I can't find the story any more.

2. Work as a freelancing developer, but don't accept large projects, only small ones where you know you can beat the time estimate in your favour. There are portals for this sort of work.

3. Doesn't need to be software development. You can do this as well writing short pieces about almost anything for the benefits of web seo. Again, there are portals for this kind of work ("gig economy"). Think $20 to $30 per piece.

4. If the gig economy is not for you: every job where a lot of stand-by time is part of the job description. Janitor for a couple of condominiums, maybe. Or you act as stand-by technician for small companies with self-hosted computer hardware (acting when you get paged).