I have been playing Get to Work pretty much everyday since its come out and I still haven't been abducted by aliens. I have tried putting him in the scientist career, putting collectibles in his inven...
well I believe it is like with the earlier Sims games then. Once you allow the aliens to abduct you and impregnate your Sim, the game assumes that you allow this to happen and so the aliens get activated. I was once abducted with a female Sim who did not come back pregnant, well guess what since then I played days ongoing without another encounter. And the sudden get up from bed to check out lights never happened either. Do you have any mods installed Tris?