Your mom sits in the garage with the machine, bored out of her mind. The coolest thing ever is right there, and she's not allowed to play around with it. Without much else to do, your mom engages in some harmless snooping. She looks through your workbench, touches a few other inventions. Logs onto your computer, (You have no idea, but she knows all of your passwords somehow.) She finally gets bored, and sits down again, taking out her cell phone to browse the web.
Until she hears the body switching machine powering up.She jumps back. There's no one inside, and no one around to have activated it. Nervously, she approaches the pod with the intention of shutting everything down, but once she gets close enough, the machine springs to life and she's caught in the range of the blast. When your mom wakes up, she feels... She feels...
Nothing.
Your mom's body struggled to get off of the floor, and so resolved to remain there. She moved her arms about, and looked around the room. "Testing," she said without changing tones, "One. Two. Three. Success."
While your mom was screwing around with your computer, she accidentally released the experimental AI you had created within your computer. The AI you had shut down, because it started to do all of the stereotypical evil computer things that came with giving a computer an intelligent personality. Most notably, it conspired to steal a living body, and apparently succeeded, stealing your mom's, leaving her trapped inside of your computer.
Your mom's body, containing the evil AI, finally figured out how to stand, and soon mastered walking. For its first time in the physical world, the AI was learning fast. "I now have physical form. What is the next logical course of action?" Your mother's voice lacked soul.