I took apart a old phone recording module from the 90s and found a strange component in the tape assembly it is a metalic box about 1/8 inch wide it has 4 wires red,white,and 1 large cable with 2 more wires
the resistance between the red and white wires is 430 ohms
resistance between other 2 wires is 288 ohms
the part number is K4 8F2C
picture below
