I just experienced my first in this game - Ethan was going outside to "Investigate". No - no! What I did was type in testingcheats on - and then shift click your sim, and press the top one "reset"....
This sounds terrible. I hope they patch this soon. I haven't had any interactions with the aliens yet, but the two sims in my family are currently ghosts. I was going to resurrect one of them with ambrosia, but I guess I'll wait until this is fixed. I guess simmers who don't want alien pregnancies could play with ghost sims until there's a patch...