WPF MultiComboBox Style - wpf

Question

I created this comboBox with checkbox-items for multiselection.
<ComboBox Height="25" HorizontalAlignment="Left" Name="MultiComboBox1" IsEditable="True" IsTextSearchEnabled="True" StaysOpenOnEdit="True" Width="240" Margin="25 0 0 0" >
<ComboBox.ItemTemplate>
<DataTemplate>
<CheckBox Name="checkBoxMulti" Width="224" IsChecked="{Binding Check_Status}" CommandParameter="{Binding Item_ID}"
Height="15" Content="{Binding Item_Name}" Checked="checkBoxMulti_Checked" Unchecked="checkBoxMulti_Unchecked">
</CheckBox>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
But im struggling to make a style out of it.
<Style x:Key="MultiComboBox" TargetType="ComboBox">
<Setter Property="HorizontalAlignment" Value="Left" />
<Setter Property="IsEditable" Value="True"/>
<Setter Property="IsTextSearchEnabled" Value="True"/>
<Setter Property="StaysOpenOnEdit" Value="True"/>
<Style.Resources>
<ComboBox x:Key="ComboBox" x:Name="ComboBoxMulti">
<ComboBox.ItemTemplate >
<DataTemplate>
<CheckBox Name="checkBox" Width="224" IsChecked="{Binding Check_Status}" CommandParameter="{Binding Item_ID}"
Height="15" Content="{Binding Item_Name}">
<!--Checked="checkBoxMulti_Checked" Unchecked="checkBoxMulti_Unchecked">-->
</CheckBox>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>
</Style.Resources>
</Style>
The combobox items are not checkboxes and it doesnt show the values from "Item_Name".
Also i dont now where to use the Checked and Unchecked Events.
I have to use the multicombobox a lot, so i want to use it as a style.