While it is likely the power feeds out to your lights and refrigerator are on separate circuits, back almost 30 years ago, who knows.
But it is more likely your return wires that may be loose. Start by putting your screwdriver on each and every wire that is not on the fuse box, but is on the return terminal strip, tighten the screw terminal, then pull the wire to see it is secure. Then do the same for each and every wire connected to the fuses on both sides.
If that doesn't fix it, you will have to go to your fridge and figure out whether it's the power feed or the return feed that isn't working. PM me for help.
mike