There is another type of beings called Yakkas which is similar to demons.They have natural tendency to do bad,There are some Yakkhas(demons) who become followers of Buddha,so that they can become good as well.They can show themselves to humans if they want by making their bodies solid or people who develop the special abilities by meditation can see them. Refer to Suttas like Atanatiya Sutta,Alavaka Sutta ect.You can find translations of those suttas by Thanissaro Bhikkhu in Google.

When someone born in Petha(Ghost) world they have no food to eat,no place to live,No drinks ,no clothes according to their kamma.They see foods but they can't take them.They stay outside walls,cross roads,at door posts of their old homes ect.If their friends or relatives donate foods and drinks in the name of dead and give that merit to dead thinking or saying "May this be for our relatives, May our relatives be happy!",by that they can have what they needed.Some people can see them or some ghost can come to the sight of people and ask help.refer to Tirokudda Kanda and Petavatthu by Thanissaro Bhikkhu in Google.

Hi Gilbert,It's great to hear you my friend.How are you?
In teachings of Buddha,he pointed out various kinds of existance of life which were appeared according to reasons,according to kamma.He said there are differences of beings because of differences of mind.
When someone born in hell(Niraya) he can't come back to the world of humans until his kamma is over.there is another way of life which is called world of ghosts(Prethas).

I'm here to wish you a pleasant dream Nutier.
Jendhamuni

All beings in Samsara are subjected ti birth and Death to be reborn again. Some spirtis and devas can establish contact with the human realm through certain channels eg dreams, hypnotic states and through certain psychics. If you are interested in these areas you might wanr to check out some of the Papers and Slide Shows presented at a Conference I attended lasy year, 'The Closer to Death Conference' ( C2RC ). The URL is : http://www.c2rc.org/papers.php.
May you grow in the Dhamma.

Hello my dear friend Gilbert, I came to wish you a wonderful weekend for you, your family and your friends, a hug, your friend Irene.

Thanks for your continued support!!!! I really appreciate it. I hope your doing well and it was good to hear from you too!

Celeste~

Je vous remercie pour vos aimables paroles ))))) Cudnego Wieczorek Nuti souhaite Rose

Thanks, have nice rest of weekend too!

merciiii nutier¡¡¡