I'm doing another "reclamation from the dirt and weeds" job on a Formula that sat for about 12 years. I noticed that few if any bulbs were lighting up, including the Check Engine light. I discovered that the very small wires on the bulbs had a bit of oxidation. Using some 400 grit sandpaper, I very gently removed the corrosion, tested each bulb with a 12 volt power supply, and all but one of the 14 bulbs were perfectly good. I also used a small metal pick to bend the metal tabs in the plastic bulb socket inward to ensure they were making good contact. This was necessary on some of the sockets.

often the sockets metal parts are cracked and seem ok but can't get a good connection to the bulb, "board" goes thru or both.
other sockets like for side markers and footlights have same problem or corrosion ate the metal too thin or ate some/all completely.

At junk yards, often can get sockets and good bulbs from nearly any car w/ 194 dash bulbs fairly easy. GM Ford and more uses these things but maybe different color and other minor things.

sometime you can "fix" corroded sockets by flipping bulb wire(s) to use other side of glass.
help when you have inspection today then find replacements later.

If you need more then 2 car bulbs, NAPA and others sell 10 or more per box of a nunber for less money then buying multiple 2 packs.

related note... Many front markers and turn lenses fade color over the years then "illegal" w/ OE white bulb. Just use 194NA etc amber bulb to pass inspection etc in most places.
Many front turn lens are made white or clear to use amber bulbs w/ them so xxxNA xxxA bulbs are easy to get.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave