Mysterious radio signal is coming from inside our galaxy

That would make for an awesome quick movie.

Start off with a younger, 20-something radio astronomy fanatic, keen to find the mysteries of the universe, working tirelessly in a job they hate, to collect the cash to construct a robust radio transmitter and receiver.
But it is OK, it is their dream, so all the trouble and distress shall be price it in the long run.

Skip forward 10 years, the fanatic is overworked, mentally exhausted, and on their lonesome, however nonetheless has mild of their eyes, as they’ve simply constructed the transmitter. They use it to ship a message, that they’ve spent years engaged on, attempting to make it as universally detectable as potential [science-y jargon], to a star 20 mild years away.
Now, all that is left is to collect the cash for a receiver and wait.

Fast ahead with transient pictures of the fanatic working away, constructing the receiver, sending the message to many different, additional away, stars, all the time alone, their well being declining with age, till, lastly, 40 years later, they obtain a signal from the primary star they focused.

The now 70-something fanatic is ecstatic, and shortly begins work on translating the message [science-y jargon]. It takes them months, however ultimately, it is performed.

The shot is from the angle of a pc monitor the fanatic is sitting at once they end translating the message. It reveals them targeted, then briefly joyous, then completely horrified. The digital camera slowly reveals the pc monitor, and on it, is the translated message:

“BE QUIET OR THEY WILL HEAR YOU”