Air carrier technician reported they ordered and installed an aileron disconnect device instead of an elevator disconnect device.

Narrative

On Day 0 I was assigned a project of a Pitch Control disconnect fault code on an aircraft with a trainer assigned to task with me to help. I was assigned the task of ordering the correct disconnect device assembly for the installation. Upon looking up part numbers for the Elevator pitch control disconnect device; we did not have the part numbers in stock of the first few part numbers I had looked up in the Maintenance System. I then went directly to the Maintenance System to look up by name 'disconnect control device assembly' to see which parts we did have in stock and if they were compatible. Then the trainer assigned to task with me had come over and pointed to the part number and told me 'it's that one' and I then with instruction and supervision ordered the part number we had thought to be the correct part. After this I had removed mostly by myself the already installed part on the plane; then The trainer removed the part from the parts bag and snaked the control cable through with safety wire and put a few bolts in and I then torqued them down after it was in place. I tried to connect the control cable from the disconnect device for a few brief minutes and decided to let the trainer take over as I was unable to connect the pin into the bellcrank and control cable. After he struggled for quite some time; he managed to get the pin into the bellcrank and control cable and I then put a cotter pin and bent it around the pin. I installed the other control cable to the other side of the bellcrank and couldn't get the cotter pin in and he took over and installed the cotter pin. After finishing up the job we performed the ops check of disconnecting and reconnecting and checking for the codes to populate on the display which a code did. After the ops check the trainer wrote up the corrective action and paperwork for the task and I put my hours of labor onto the write up. A couple days after I was informed that we had installed the Aileron disconnect device part number onto the elevator disconnect device assembly location and that the aircraft was grounded once the problem was alerted to. Cause: The event was caused by miscommunication and inexperience and lack of assuring the part number was for the correct application. Suggestions: In the Maintenance System; label the parts more clearly which system they are for and or indicate the part number more clearly to avoid confusion between parts.