Got  a call from a Washington DC number telling me they were Fed Ex and had a package and asking for my business address.  I did not provide and instead asked for a callback number,  This number was provided, and as noted about was an adult chat line.

Got a call from this number; the phone identified it as "Fed Ex." However, I couldn't switch over - said, "Hello" and received no answer. Phoning the number back, the recorded voice identified it as "the hottest chatline in America." I hung up, but expect a charge. Be warned - don't phone back.