Is it possible to make the contents of a ScrollViewer scroll with the mouse wheel?

Question

I'm on a team of developers working on a new WPF application. We've got a usercontrol on the MainWindow which has a ScrollViewer. We've got VerticalScrollBarVisibility="Auto" set, which works fine, if the contents within the ScrollViewer become larger than the available space for the ScrollViewer. However, what doesn't happen, which I wish would happen, is the user cannot scroll the contents with the mouse wheel. In other places where we're using DataGrids, if the content of the DataGrid is larger than can be displayed vertically, the user can scroll the contents vertically using their mouse wheel. But they cannot do so within the ScrollViewer in the user control on MainWindow. If it's possible to make the contents scroll vertically with the mouse wheel, how is it done?

Here's a snippet of the ScrollViewer, with content removed for brevity:

<ScrollViewer
    Grid.Row="1"
    Margin="0,20,0,0"
    Width="300"
    VerticalScrollBarVisibility="Auto"
    HorizontalAlignment="Left"
    VerticalAlignment="Top">
    <StackPanel>
        <Expander
            x:Name="PeopleSideExpander"
            IsExpanded="{Binding PeopleSideIsExpanded}"
            IsEnabled="True">
            <Expander.Header>
                <Button
                    x:Name="tilePeopleSide"
                    Content="People Side"
                    Command="{Binding PeopleSideExpanderCommand}"
                    Cursor="Hand" />
            </Expander.Header>
            <ListBox>
                <ListBoxItem>
                    <Button Name="tileAgency" Content="Agencies" Command="{Binding ViewAgencyCommand}" />
                </ListBoxItem>
                <ListBoxItem>
                    <Button Name="tilePerson" Content="Personnel" Command="{Binding ViewPersonCommand}" />
                </ListBoxItem>
                <!-- Several other ListBoxItems removed for brevity -->
            </ListBox>
        </Expander>
        <Expander
            x:Name="HardwareSideExpander"
            Grid.Row="1"
            IsExpanded="{Binding HardwareSideIsExpanded}"
            IsEnabled="True">
            <Expander.Header>
                <Button
                    x:Name="tileHardwareSide"
                    Content="Hardware Side"
                    Command="{Binding HardwareSideExpanderCommand}"
                    Cursor="Hand" />
            </Expander.Header>
            <ListBox>
                <ListBoxItem>
                    <Button Name="tileEvent" 
                            Content="Event" 
                            IsEnabled="False"
                            Foreground="LightGray"
                            Command="{Binding ViewEventCommand}" />
                </ListBoxItem>
                <ListBoxItem>
                    <Button Name="tileInstrument" 
                            Content="Instrument" 
                            IsEnabled="False"
                            Foreground="LightGray"
                            Command="{Binding ViewInstrumentCommand}" />
                </ListBoxItem>
                <ListBoxItem>
                    <Button x:Name="tileHardwareProficiency" 
                            Content="Proficiencies" 
                            Visibility="Collapsed"
                            ToolTip="Not Implemented" />
                </ListBoxItem>
                <ListBoxItem>
                    <Button x:Name="tileSolution" 
                            Content="Proficiency Solutions" 
                            Command="{Binding ViewSolutionCommand}" />
                </ListBoxItem>
            </ListBox>
        </Expander>
    </StackPanel>
</ScrollViewer>