Can ethyl alcohol helps to get the essential oil out of the leaf?

What leaf?: Ethyl alcohol is the same alcohol that people drink. I am not sure where you can buy it, outside of buying grain alcohol from the liquor store or from a chemistry lab. Are you sure you aren't referring to isopropyl alcohol or rubbing alcohol? Anyway, I am not at all sure as to the type of leaf for which you are referring? Nor is it clear what you mean by essential oil? Sorry.

Yes and no: Eo's are often distilled or extracted in large scale processes. Depending upon eo alcohol extraction may be useful. Small scale extraction of eo generally yields small amounts at high cost.