unauthorized opening of mail and keeping a check but not cashing it.?

Answer 1

Well, if you know there is a check in it you must have already opened it. Send the check back in the mail to the issuer.
If you "cash" it, you will be in trouble!

Answer 2

I have personal knowledge of this question ... in a way. When I was in the US Navy as a Personnelman, I had the responsibility of distributing the mail to our unit.

When my wife stopped writing to me, I was devastated. Then I saw her UNIQUE handwriting on a letter addressed to an acquaintence of ours who had recently been dropping by the house, usually bringing gifts.

One night, in total frustration, I opened a particularly huge letter from her to this person. It detailed her plans to keep my money sent to her (80% of my check), dump me, and marry this person. I went NUTS!

Stupidly, instead of throwing it overboard into the ocean, I told my superiors about me opening the letter. They promised nothing would happen. Instead, I was referred to NCIS and threatened with a FEDERAL violation of opening mail without authorization. After I explained the circumstances, the charge was reduced to Article 15 and to my unit level. EVEN SO ... I was reduced to grades in rank, had to pay humdreds of dollars in fines, given a horrible job evaluation and eventually ran out of the Navy.

SO ... my advice, JUST SAY NO! Do NOT open any mail that is NOT addressed to you, regardless of any actions you may or not do after that. The act alone is a Federal offense punishable by YEARS in prision.