How do I get to the haunted house in Pokemon diamond I know its in Eterna Forest but where?

go to the enterna city. go there at night with lots of strong pokemon. there are a lot of guards. go up to the tv. it's easy to catch because its only lv 15. unless you know the master ball cheat use an ultra ball.

use a quick ball!!!!! its easier.

there was a really insulting edit. i deleted it though.