Such a cute wedding favor idea for evening weddings or even as just an added treat for guests staying in your hotel block. Whether it is a candy bar with all yours and your significant others favorite candies or candies matching your color scheme or candy that matches your theme a cute cellophane bag or jar with a sticker on it saying "Sweet Dreams". Or maybe a large candy bar at each placesetting with a candy wrapper (you can buy them already printed or buy the wrappers and print them yourself) saying "Sweet Dreams" or a prefilled jar with that same label (and maybe even a cute ribbon).
Or if you already have a wedding favor in mind you could ask the hotel you have your wedding block at to leave a candy bar or jar or bag with "Sweet Dreams" on each persons bed or in their room the night of the wedding (kind of like a mint on the pillow kind of idea).
You get the idea....
As always if your having any problems coming up with ideas for your wedding please feel free to contact me and I'll do my best to come up with an idea for you.