Paste this code into kaxaml
You'll see that clicking on the label toggles the checkbox.
[See this SO answer by Kent]
<Page
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<StackPanel>
<CheckBox IsChecked="{Binding IsChecked, ElementName=checkbox}" Content="Hello">
<CheckBox.Template>
<ControlTemplate TargetType="CheckBox">
<ContentPresenter/>
</ControlTemplate>
</CheckBox.Template>
</CheckBox>
<CheckBox x:Name="checkbox" Content="A normal checkbox"/>
</StackPanel>
</Page>