Hello
Some other things to try doing are to have him be friends with other aliens ,
having a high level in the logic skill can help ,
having space rocks at his home ,
and using the " out of this world" desktop that is unlocked with the science career at level 10 to "contact aliens"
MC Command Center mod has an occult module with abduction settings.
http://modthesims.info/download.php?t=551680
This link thread provides help for the MC Command Center Mod. If you decide to use it and you have questions about the settings, you can post about it there, and there are helpful simmers there that will help you.
http://forums.thesims.com/en_US/discussion/837115/need-help-with-mc-command-center-settings-ask-here
I hope that your sim gets abducted soon!