so that's where your interest comes form - most just think I am nuts! LOL! Just curious - where do you live?
Most moths will congregate around an ordinary porch light. Using a black light, not a blue light, will bring in a larger variety. your garage door might work but the idea of the sheet is to attract "through" the sheet in order to keep them there and it is a great way to learn shape i.d. I have not personally used the light/sheet but was with a friend once who did. I recently met a woman at a conference (she does research on the decline of the giant silks (Saturniidae)) who suggested I use the light/sheet so I may try.
Before I go any further, I have to recommend a book to you. It came out in 2002 and is written by a guy from CT. I live in NH so it was most helpful since species are similar. it is a fun, informative book and a very easy read. The book is Discovering Moths: Nighttime Jewels in Your Own Backyard by John Himmelman One of the most helpful things in this book is his page of Moth Family Silhouettes - I use this page as a starting point when identifying things either on this site or on my own. Anyway, it is a must have book if you ant to learn night flying moths especially if you live in the northeast. He also has a website – I linked it below.
I have 6 different species of Saturniidae going right now and at least 100 larvae. I typically do less than this but I didn’t release a gravid female luna soon enough and ended up with about 100 of her eggs! Yikes! Many are spinning so it is getting easier but my io’s are getting to their 5th instar and are eating like crazy!
OK, that’s it for now, as I have to get some work done!
Later,
lele
p.s. if you get addicted the oooh and ahhh will come along with it 
CT moths