How to fix a socket that works and doesn’t work and has a switch in the cord. It is a small one the size of a chandelier bulb.

I'm going to take a wild guess that the previous home owner put the blanks up because they had the same problem and didn't want to fix it. You likely have a short circuit and need to track down where the short is occurring. I'd remove the bulb from the fixture, unhook each of the wires that you connected before, and use a multimeter to test for "continuity" between the wires on each run (e.g. hot to neutral, hot to ground, neutral to ground for the line to the switch, for the light fixture without a bulb, and anywhere else that was previously disconnected). If you don't have continuity with a simple low voltage tester, then the problem could be arcing that only occurs when 120V is applied. Either way, get this fixed before turning the breaker back on with this fixture wired.

If the switch you are replacing is in an electrical box that is grounded there is a possibility that insulation in one if the hot wires is compromised and shorted to the box. This would create a direct short when the wire becomes energized and cause the breaker to trip.

The other possibility is that this switch controls an electrical outlet in addition to a light. Switched outlets are common in living rooms and some bedrooms. In bedrooms with a switched outlet a ceiling light may have been added after the original installation so that the switch controls both. In your case you may have replaced the switched outlet and wired it incorrectly. The error may not have become obvious until you came to work on and replace the switch.