InvokeCommandAction.xaml

<ListView IsItemClickEnabled="True" 
            ItemsSource="{Binding Items}">
    <i:Interaction.Triggers>
        <i:EventTrigger EventName="ItemClick">
            <i:InvokeCommandAction Command="{Binding ItemClickedCommand}" />
        </i:EventTrigger>
    </i:Interaction.Triggers>
</ListView>

ViewModel.cs

public ViewModel()
{
    Items = new List<string> {"Item 1", "Item 2", "Item 3"};
    ItemClickedCommand = new DelegateCommand(ItemClicked);
}

public void ItemClicked()
{
    // react to the event
}