Redirected from another post I made about this to provide a little more info. In one instance, I know it wasn't a pet because the Sim in question, a young adult, has no pets. There is also nothing that makes noise on the floor where her bed is. She is living on a residential lot in a house I built, not an apartment, and she wasn't getting up to look at anything. She was just popping out of bed and standing there. If the bug repeats on her lot, I'll send you the save file.
I just finished deleting cache files according to the instructions under a thread for that. Interestingly, I noticed a string of exceptions that all said something about an item in inventory not corresponding to any category. It made me realize that one of the sims that was having the issue had been playing fetch with one of the family dogs and still had the ball clutched in her hand. I couldn't get her to let it go until I instructed her to specifically give it to one of the dogs. After it was out of her hand, she slept.
I saw someone else mention this started happening after they installed Moschino. I had just recently installed that, too. I've had Cats and Dogs ever since it released and never had this issue before. The next time it repeats for any of my sims, I'll send a save file. Thanks!