Public Class UCT
    Public Shared ReadOnly isTestProperty As DependencyProperty = DependencyProperty.Register("isTest", GetType(Boolean), GetType(UCT))
    <Category("Common")>
    Public Property isTest As Boolean
        Get
            Return CType(Me.GetValue(isTestProperty), Boolean)
        End Get
        Set(ByVal value As Boolean)
            Me.SetValue(isTestProperty, value)
        End Set
    End Property
End Class

<UserControl x:Class="UCT"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             xmlns:my="clr-namespace:WpfApplication1"
             xmlns:UserControls="clr-namespace:WpfApplication1" mc:Ignorable="d" 
             xmlns:src="clr-namespace:WpfApplication1"
             x:Name="MyEventControl"
             d:DesignHeight="22" d:DesignWidth="300">
    <UserControl.Template>
        <ControlTemplate TargetType="{x:Type UserControl}" >
            
            <Grid>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition />
                </Grid.ColumnDefinitions>
                <CheckBox x:Name="UC" VerticalAlignment="Center" 
                          IsChecked="{Binding Path=isTest, RelativeSource={RelativeSource FindAncestor, AncestorType=src:UCT, AncestorLevel=1}}"
                          Content="{Binding Path=isTest, RelativeSource={RelativeSource FindAncestor, AncestorType=src:UCT, AncestorLevel=1}}">
                </CheckBox>
                <Label x:Name="UT" Background="#FFE2E2FF" 
                       BorderBrush="#FFEA1212" 
                       Padding="0" 
                       VerticalContentAlignment="Center" Grid.Column="1">
                </Label>
            </Grid>
            <ControlTemplate.Resources>
                 
            </ControlTemplate.Resources>
            <ControlTemplate.Triggers>
                <Trigger Property="IsMouseOver" Value="true">
                    <Setter TargetName="UT" Property="Content" Value="IsMouseOver" />
                    <Setter TargetName="UT" Property="Background" Value="White" />
                </Trigger>
                <DataTrigger Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=src:UCT, AncestorLevel=1}, Path=isTest, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}" Value="true">
                    <Setter TargetName="UT" Property="Content" Value="isError" />
                    <Setter TargetName="UT" Property="Background" Value="Red" />
                    <Setter TargetName="UC" Property="Background" Value="Red" />
                </DataTrigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>
    </UserControl.Template>
</UserControl>