I'm not at all familiar with a mod like that. I don't think I've ever had sims autonomously go to sleep until their energy is less than about 25-30%. If they attempt to do that then I just cancel it anyway and keep them going until they're truly thrashed , say 5-10% energy before I let them sleep. There is a discussion involving a few sleep mods, none of which sounds like what you want though , here
http://modthesims.info/showthread.php?t=474926&c=1&ht=&page=1&pp=25#startcomment . The most likely sites ( at least for me ) to find Sims 2 mods are here(Insim), Simlogical, MTS, Simbology, Simwardrobe, Cyjon and MATY (in no particular order). Simbology has a few repositories of retired creators items , like Tunaisafish, Christianlov and a few others. The Sims 2 Graveyard has some of XPTL's older items and sections for PCSims ( Sims2modboard, Katy76) and a few others. Sorry I can't help more. If you do manage to track it down please post a link so if others want it in the future they'll have that info. Good luck!
