need help electronic/relay problem phone horn

I need to ring a phone that activates a loud ass horn. Phone has no audio ports. I'd be tapping into the 2 wires that connect from phone circuit board to the phone ring speaker.



Inside the handset, the 2 wires show .035-.045 VAC (probed with multimeter while the phone "rings") and connect to an 8 Ohm 2W speaker inside the phone. This 8 Ohm 2W speaker needs to be replaced with a very loud horn or buzzer.



-I purchased a generic 12VDC piezo horn. Need to feed it 12VDC when phone rings. That's all.



I'm stumped. Low signal relay? Some type of inline amp? I can solder a bit, and have only a very basic understanding of this stuff.



Do I look for a low signal relay? like .03VAC to 12VDC?



Thank you