SafeZone

Reupload of Koosemoose's Safe Zone mod Safe Zone - Nexus Mods

Displays a Status Effect (Safe) when you're in range of structure that stops monster spawning (such as workbench or torches). Additionally, by pressing a key (Default: G), you can show a ring around any such structures (a spinning ring identical to what you see around a workbench when building. Press again to hide the rings.

The status effect doesn't do anything and is purely informational, to show when you're in an area that can spawn monsters. Showing the rings can be useful if you're trying to ensure there is nowhere in your base that monsters can spawn. Since it shows individual rings around the no spawn areas, lots of them can make it a bit visually overwhelming (there's no reliable way I've found yet to show something that indicates the overall no spawning area), so you'll likely need to double check an area that looks like it's outside of rings by stepping into it and seeing if the Safe status effect shows.

Note: Showing the rings is pretty intensive, so I would advise only having it on when you need it.