Use the following trick to have your Sim get abducted by aliens (the icon is a green saucer). Buy a telescope at the "Buy" menu and select it. Choose the "Stargaze" option. Note: The "Spy" option will not work. Suddenly a light will appear from the sky and your Sim will be abducted. A few hours later, the Sim will return. If that Sim has a job, do this on Saturday or Sunday to avoid missing work.