-- PUT THIS IN A LOCAL SCRIPT

local UIS = game:GetService("UserInputService")

local switch = false

​

UIS.InputBegan:Connect(function(input)

    if input.UserInputType == Enum.UserInputType.Keyboard then

        if input.KeyCode == Enum.KeyCode.F then -- replace "F" with key of your choice

            if switch == true then

                -- put what ever you want to happen when OFF

                print("Its off!")

                switch = false -- must keep this for it to work

            else

                -- put what ever you want to happen when ON

                print("Its on!")

                switch = true -- this also has to be here for it to work

            end

        end

    end

end)