where can i get free designs for street banners?

i'm involved in home automation and intends to advertise using street banners but i cannot come out with the design.pls help.

off course, you go and click google search engine
You're not gonna find any that suits your very specific needs. You should google for a while using keywords like "free", "banner", "home automation", "add", etc. in several combinations (not all at once or you'll find nothing), then choose the ones you like best. When you have your selection, try combining the good aspects that you like of them, and make your own design (so nobody accuses you of stealing their work). Good luck! .