Virtual Three-way Switch, Systems and Methods

A system may be provided that includes an adaptor connected to a dimmer and virtual three-way switch. The virtual three-way switch can be for a lamp plugged into wall-switched receptacle. The virtual three-way switch can control a lamp, appliance, or any device that is connected to the three-way switch by one or more of the connected switches, independent of the position of the unused switch. The virtual three-way switch may include a power input that receives power from a first power source, a sensor detecting a state change of a second power source, a user input sensor receiving a user command, and a power output delivering received power at a rate as function of the state change and of the user command. The virtual three-way switch can be connected to a user input device that is waiting to receive a command. The power output can deliver power to a connected device.