When you dream of seeing or using the jack in a dream, then such dream represents the harmony of your life. The jack in a dream could also show the person who is named Jack.
Dream dictionary: Jack dream meanings
When you dream of jack-o-lantern means that you are looking forward for some kind of celebration.
Dreaming of a jumping-jack, denotes that idleness and trivial pastimes will occupy your thoughts to the exclusion of serious and sustaining plans.
Dreaming that you are angling for jack, suggests you to be more prudent.
Being cheated or deceived by others.
You will be forced to make important decisions.