Delete Sheet If Contains

[snb]

You'd better use:

Sub snb()
  on error resume next

  with getobject(sourceFile)
    .application.displayalerts=false

    for each sh in .sheets
      sh.cells.find("searchstring",,,1).clearcontents
      if err.number=0 then sh.delete
      err.clear
    next
    .close true
  end with
end sub

You should be aware that a workbook contains at least 1 worksheet.
So if all worksheets contain the string you are lookinng for, the last sheet will not be removed, but the searchstring will in the code I'm suggesting.