I found this under my 69 442 dash today while fishing for something else. It's not plugged in, but there are a lot of wires and fuses. The back says something about complying to FCC part 15 rules. Maybe something to do with a radio or CB?

 

Alarm or Remote Start is what it looks like to me.

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Did a search for the FCC# . looks like an alarm reciever.

https://fccid.io/ELV55AAL736R

 

That makes sense, thanks guys.