参考其他人demo,做了小修改。

 <Style TargetType="CheckBox" >
            <Setter Property="Template" >
                <Setter.Value>
                    <ControlTemplate TargetType="CheckBox">
                        <DockPanel>
                            <ContentPresenter DockPanel.Dock="Left" VerticalAlignment="Center" Margin="10 0"></ContentPresenter>
                            <Grid >
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition Width="40"></ColumnDefinition>
                                    <ColumnDefinition Width="40"></ColumnDefinition>
                                </Grid.ColumnDefinitions>
                                <Rectangle Grid.Column="0" Grid.ColumnSpan="2" Fill="Gray"></Rectangle>
                                <Border x:Name="gborder">
                                    <TextBlock x:Name="txtInfo" Foreground="White"  VerticalAlignment="Center"  HorizontalAlignment="Center"></TextBlock>
                                </Border>
                            </Grid>
                        </DockPanel>
                        <ControlTemplate.Triggers>
                            <Trigger Property="IsChecked" Value="true">
                                <Setter TargetName="gborder" Property="Grid.Column" Value="1"></Setter>
                                <Setter TargetName="gborder" Property="Background" Value="LightBlue"></Setter>
                                <Setter TargetName="txtInfo" Property="Text" Value="On"></Setter>                               
                            </Trigger>
                            <Trigger Property="IsChecked" Value="false">
                                <Setter TargetName="gborder" Property="Grid.Column" Value="0"></Setter>
                                <Setter TargetName="txtInfo" Property="Text" Value="Off"></Setter>
                            </Trigger>
                            <Trigger Property="IsChecked" Value="{x:Null}">
                                <Setter TargetName="gborder" Property="Grid.Column" Value="0"></Setter>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

 <CheckBox Content="开关" Width="200" Height="40"></CheckBox>

　　效果如下：