How to import text file data into single item plain text column via powershell

How to import text file data into single item plain text column via powershell?

I tried below ps which works but strangely it puts system.object in rich text column- plain text.

$metadata1 = Get-Content C:\ourfolder\metadata.txt
$title  ="test"
$site = Get-SPSite http://url
$web = $site.RootWeb
$listName = "mylist"
$list = $web.Lists[$listName]

Write-Host "test"

  $SPItem = $list.Items | where {$_['Title'] -eq $title }
 $SPItem["Metadata"] = $metadata1 



$SPItem.Update()

text file content is like below format

<List Header=""  XmlVersion="2"  HAlign="Center"  Height="0"  Width="0"  Culture=""  Calendar=""  ToolbarPosition="Top"  RTL="False" ShowProgressForm="Always"  TabAnimation="FadeIn"  ShowHeader="False"  ShowToolbar="True"  ShowPrint="False"  ShowAlertMe="False"  ShowCancelButton="True" ShowAttachments="True"  SaveLocalizations="True"  LocalizationsUrl=""  ToolbarImageOnly="False"  ToolbarTooltips="False"  ShowSaveButton="True"  ShowSaveAndExitButton="True" AllowNew="True"  AllowDelete="True"  RequiredFieldBorderColor="Blue"  HelpPage=""  MarkRequiredFields="False"  AsyncValidation="False"  AsyncLoadCompleted="False" AsyncSaveCompleted="False"  AsyncDeleteCompleted="False"  FontSize="0"  ShowUserLoginName="False"  FontFamily=""  PrintControls=""  PrintHeaders=""  PrintTemplate="" PrintCaption="" >
<Includes>&lt;script type=&quot;text/javascript&quot; src=&quot;/Style Library/ourscript.js&quot;&gt;&lt;/script&gt;




&lt;script&gt;
function setupDrop(ID, form, returnMapping){
        var forMapping = 

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MCTS Sharepoint 2010, MCAD dotnet, MCPDEA, SharePoint Lead