WPF ListBoxItems with DataTemplates - How do I reference the CLR Object bound to ListBoxItem from within the DataTemplate?

I have a ListBox, that's bound to an ObservableCollection.

Each ListBoxItem is displayed with a DataTemplate. I have a button in my DataTemplate, that when clicked, needs a reference to the member of the ObservableCollection it's part of the DataTemplate for. I can't use the ListBox.SelectedItem property because the item does not become selected when clicking the button.

So either: I need to figure out how to properly set ListBox.SelectedItem when the mouse hovers, or when the button is clicked. Or I need to figure out another way to get a reference to the CLR Object bound to the ListBoxItem that the button belongs to. The second option seems cleaner, but either way is probably OK.

Simplified code segment below:

XAML:

<DataTemplate x:Key="postBody">
    <Grid>
        <TextBlock Text="{Binding Path=author}"/>
        <Button Click="DeleteButton_Click">Delete</Button>
    </Grid>
</DataTemplate>

<ListBox ItemTemplate="{StaticResource postBody}"/>

C#:

private void DeleteButton_Click(object sender, RoutedEventArgs e)
{
    Console.WriteLine("Where mah ListBoxItem?");
}