In my area, there is a Pediatric Ventillator Program that holds a 4-day 8 hr course to become trach-vent "certified"; rather competent. In HH, I did the initial course, the two-day course to become a educator, as well as maintained T/V competences each year.
Find out if your HH company helps their nurses become "trach-vent competent" and start from there. You will most likely receive theory, skills lab, paper test, then precept with a T/V nurse for at least 16-24 hrs before you can start caring for T/V pts, if you are have not already done so.
The nursing "shortage" I do see is T/V nurses in HH; sometimes there are not enough nurses for their cases. I usually had 2 cases when I worked in HH, and at least 1 or both were T/V.
I have yet to hear about a "ventilator certification"; just only the program I've had.
Hope this helps! Good luck!