I've been having quite a few alien abductions happening in my game, too. I just thought because some of my sims are friends with some aliens in my game. Three of my male sims (one spellcaster, one vampire and one human) got abducted on the same night, two of them being abducted 25 sim seconds from each other and the other getting abducted a few sim hours later. I do use MCCC, but I have not made any changes to alien abductions in it.
It's not much of a bothersome to me, I actually find this more hilarious than anything, but I know this will not settle well with other players that might find this extremely annoying.