Notice to WRVR is a paper note in Fallout 4.
Location
The note can be found inside the WRVR broadcast station, on a desk near the ladder.
Transcript
Dear WRVR members,
It has come to our attention that your station is in close proximity to one of the tower sites in our newly planned Relay Tower network. Your station may experience periodic intereference or disruptions when we deem it necessary to broadcast.
If you have any questions or concerns beyond that please contact your nearest military branch.
Thank you and have a great day!