Dear Printer Repair Man:
Please come to my house and check my printer.
Every time I use the printer - and I am away while it prints - my papers are wrinkled, even shredded. Sometimes the ink is blurred .. I hope that you can find the problem!!
Sincerely,
Concerned Computer Owner
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Dear Concerned Computer Owner:
While you were gone today, I checked your printer, and I found your problem. Please see the video for the answer.
Sincerely,
Your Printer Repair Man

 (sent to a colleague of mine via email)