My adorable, innocent cat has a problem. She likes to get high! (No, I do not give her drugs. I only give her Wellness brand cat food and special treats that promote dental health.)
She's only three years old, but she's chewed through at least eight laptop power cords ... two of them in the last month and a half. I've only caught her doing it a couple times. One time I saw that she bit down and got a little spark. I think that is why she does it! To get high!
She doesn't chew any of the other plugs in the apartment. I've tried coating the cord with things she's not supposed to like (citrus, hot sauce, nail polish, nail polish remover ...). It doesn't work. She cannot stop chasing that high. She has an electric monkey on her back!
If I start noticing her personality changing, I will have to stage an intervention.

In addition to behavior changes, you should look out for missing jewelry or money and other, the sudden presence of untrustworthy cats in tiny denim vests and leather wristbands.