Help Loach Stuck In An Ornament!

How long has it been in there, long enough that it should have got itself out by now? If it has only been a short time, turn the lights off and see if it can get out by itself. If it can't, the only option is to very carefully destroy the ornament around it. Breaking bits off with pliers is one way, keeping it under water all the time, and removing the broken off bits immediately so they don't fall to the bottom of the tank.

Fish can panic and rush into the nearest bit of cover whether it is suitable or not. Other fish are very curious and will explore places where they won't fit. It is always worth examining any decor to see if a fish could get stuck, and plug those places before putting it in the tank. Something like a blob of silicone sealant will seal off a potential hazard.

Gald to hear the fish is OK.
Make sure you use aquarium safe silicone, which means either get very expensive stuff from a fish shop or read the small print very carefuly on a tube from anywhere else. Most silicone for diy has an anti-mould agent in it which will harm the fish and the bacteria in your filter. And let it dry for 48 hours before putting it in the tank.
Don't seal the ornament completely water tight or when you put it back in it will float. leave a small gap for water to get inside, but too small for a fish.

I have a terracotta flowerpot on its side in my betta's tank and the hole in the bottom is just the right size for a betta to get stuck in. I siliconed a small square of plastic craft mesh over the hole rather than fill the entire hole with silicone.