On my days off I'm bored as hell. What do you guys do to keep yourself entertained?

Because of my work schedule (12 hour shifts), I get 4 days off per week. During two of those days my fiancee is at work, so I'm at home by myself bored as hell. My friends are only available on the weekends, but usually my fiancee and I are doing something on the weekends. On the weekdays when I'm off, I can't find anything to do (that doesn't require spending a ton of money). Looking for ideas.