You can riff on something as simple as this:
$cutoffdate = ([DateTime]::Today).AddDays(-3 * 365) # about three years
Get-Childitem -path c:\temp -recurse | where {$_.lastwritetime -lt $cutoffdate -and -not $_.PSIsContainer} | select FullName, Length, LastWriteTime, LastAccessTime | export-csv c:\temp\oldstuff.csv -NoTypeInformation
Adjust your path , cutoff date, and properties as needed.
--- Rich Matheisen MCSE&I, Exchange Ex-MVP (16 years)