[BY DESIGN] [GTW] NPCs that are in game but not in manage households

Recently I started noticing NPCs walking around that I couldn't find in manage households.I looked very thoroughly, but they really aren't there.

I know this is similar to the issue with ghosts: http://answers.ea.com/t5/The-Sims-4-Bug-Reports/single-ghost-in-the-houses-but-not-in-the-manage-households-tool/m-p/4153467/highlight/true#M6615

I've actually had that happen too, so I clicked 'me too' there. This however has something different about in that these sims are still alive. The ghosts generally were in manage households before they died, these sims have never even been in manage households. (I can however imagine that in a technical sense these issues are at least linked, if not actually similar or mostly the same.)

We've already had a pretty extensive discussion on this on the forums: http://forums.thesims.com/en_US/discussion/833862/npcs-that-are-in-the-game-but-arent-in-manage-households/p1

This is what we know:

- It only started happening after the release of Get to Work, possibly only for people who have GTW (not sure of that)

- Most of these sims are generated for the purposes of one of the active careers, mostly the detective career (co-workers, suspects, etc). Yet, at least one person reported having seen a 'stealth sim' (that's what we decided to call them) without having a police officer sim (not sure if that person had any sims in the other active careers).

- These sims do count towards the population limit of 180 sims.

- repair game (and packs, separately) has no effect on the issue.

- [Added in edit] It appears that these sims have a hidden trait called 'guilty criminal' which can only be uncovered/removed by using a mod. (more on that in the forum thread linked above)

These are the known 'fixes':

- adding the stealth sim to a played household (via cheat or by befriending them) and deleting them from there.

- the use of 😇 mod(s), I forgot which, but I don't ever use mods. Also not sure what they do exactly.

Anyway, this doesn't prevent more stealth sims appearing, besides we much prefer to have control over all the sims in our worlds.

It will be much appreciated if this can be fixed permanently.