You can usually find Pokemon like that in a cave.
Ghastly can be found in Sprout Tower in Violet City.
Yes. you can find ghastly at lost tower or Eterna Forest. You can get haunter but i don't know where.
Pokemon ruby's version IS Pokemon ruby.
go to maps 23 or 24
Bellsprout tower at night time.
Go to Mt.Pyre, then go to the left.There should be a door, go out of the door and go up.Then start walking in the grass.Soon you will find a vulpix, beat him/her up.Then walk around for about 10-20min.A ghastly should appear. Lies^^^ you CANNOT catch ghastly or haunter in the wild, at least not in (ruby,saphire, or emerald) noobieee.
To get Gastly you have to go to sprout tower at night.
I have herd ghastly is in the sprout tower
Arceus is not possible to find in Pokemon Ruby. It was released in 2007 with Pokemon Diamond and Pearl
You can't in ruby.
You can find all kinds of pokemon.
Ghastly will evolve at level 20.