Why do my lights turn on when I plug a device into a nearby outlet?
If it's a remotely controlled dimmer, it's likely that RF interference from the switching power supply is causing the issue.

You may need an AC mains RF filter, AKA a noise filter, and possibly an RF choke (ferrite core filter) for the line cord, cord to the laptop, or both. You can probably find them in a local hardware store or electronics shop, as well as online.