How to delete old profiles with script - powershell

Question

So I am trying to adapt this code I got from another post for the needs of my current organization. Please see below code:
$Admin = "Administrator","Public","Default","Administrator"
foreach($file in Get-ChildItem C:\Users\)
{
if ($file -in $Admin)
{
Write-Host = "`r`nUser account is" $file ". This is an Administrator Account, it will not be deleted."
}
else
{
Write-Host = "`r`nUser account is" $file ". Checking profiles age..."
$FileDate = (Get-item C:\Users\$file).CreationTime
Write-Host = $FileDate
$TestDate = (Get-Date).addDays(-30)
Write-Host = $TestDate
If ($FileDate -lt $TestDate)
{
Write-Host = "Since" $file "is older than 30 Days (" $FileDate ") it will be deleted."
$UserAccountPath = "C:\\Users\\$file"
$WMIQuery = "SELECT * FROM Win32_UserProfile WHERE localpath = '$UserAccountPath'"
$UserProfile = get-wmiobject win32_userprofile | where localpath -eq c:\\users\\$file
Remove-WmiObject -InputObject "$UserProfile"
}
else
{
Write-Host = "Since File is dated less than 30 days old (" $FileDate ") it will not need to be deleted."
}
}
}
After running this I get the following error:
Remove-WmiObject : Object reference not set to an instance of an object.
At line:28 char:17
+ Remove-WmiObject -InputObject "$UserProfile"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Remove-WmiObject], NullReferenceException
+ FullyQualifiedErrorId : System.NullReferenceException,Microsoft.PowerShell.Commands.RemoveWmiObject
Any help is appreciated.

Answer 1

Basically, the mistake is in this line:
$UserProfile = Get-WmiObject win32_userprofile | Where localpath -EQ c:\\users\\$file
$UserProfile is null, and will always be null, because the equality comparer -eq is looking for an exact match, to put it into perspective:
'C:\some\path' -eq 'C:\\some\\path' # => False
[pscustomobject]#{
localPath = 'C:\some\path'
} | Where-Object localPath -EQ 'C:\\some\\path' # => Null
To fix this, you can do the following:
# $UserAccountPath = "C:\\Users\\$file" // This line is not needed
#
# DirectoryInfo objects have a FullName property for their Absolute Path
$UserProfile = Get-WmiObject win32_userprofile | Where-Object localpath -EQ $file.FullName
Remove-WmiObject -InputObject $UserProfile
$UserProfile = Get-WmiObject win32_userprofile | Where-Object localpath -EQ $file.FullName
$UserProfile.Delete()