I have a 1999 Honda Civic, 110,000 miles that occasionally (every 3-4 months) stalls. Once at a stop light, once while driving decelerating to turn, once after sitting all night in garage. All three times it started after a few minutes. I have heard that after 10-12 years electrical parts should be replaced like the main relay, ignition control module, coil, etc. Is it possible to narrow it down or do I have to replace all to fix problem? (the computer doesn't show any codes)

I would replace the Ignition Control Module (ICM) and coil:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-4.html#post265896

If the CEL comes on and goes off normally, when the ignition switch is turned to ON (Position II), then the ECM is likely fine.