Go to wishcash pond if u find medicham & ekans there go near to them.do this for some days
in the game.one day they won't be there then go to the bulletin board.ekans will be there,
check the bulletin board there will be a rescue saying that medicham needs help in wish
cave.accept it and walla wish cave is open.

ya that rite

Get Hm surf.go to the wishcash pond and find medicham&ekans there go near to them.do this
for some days until you found ekans alone.The next day,go to the bulletin board and check
it.
It will saying MEDICHAM needs help in wish cave.accept it and you open the wish cave.

note:If you enter the wish cave,no metter how high your level,you will at lvl 1.MEDICHAM
is on B20F/20F.