This part even does not have a part number. Looks like it was not serviceable by design.

Gene.

Not sure if you mean me et25dqrbw00 Whirlpool but the inside of the door is filled with a hard foam. I cut out the foam near where the water tube went in and found the 1/4" water tube inside a slightly larger plastic tube which I carefully cut into and pulled out a section of the 1/4" water tube an spliced in a piece of 1/4" water tubing using the connectors they sell here. It worked fine . I did not try to replace the small amount of foam I hacked out -seems to have no effect on temperature of fridge. There is a metal coil that the water tube has to go thru as it passes from the door to the fridge to keep the water tube from getting cut make sure that metal coil is secure inside the fridge door and passes thru the hole in the bottom of the door(duct tape).

I have a water line that is leaking inside the door of a GE fridge with this model number: PSF26NGTDWW

I took the face plate and electric components out kind of like in this video: https://www.youtube.com/watch?v=lnEV4ZHC_W4

But it wasn't abundantly clear where the water line hose was inside there. Can you please let me know if this is DIY able. I am VERY handy and have done many fridge repairs in the past.