All you have to do is rock the horsey cradle thing. Then you will go to this ghost dimension and fight the demonic baby. Then suck up the ball with you p.3000 and spit it back at him(this may require use of the control stick)(yellow stick)
in the twins room once you beat the twins.
walmart
in the basment
trapped in a portrait on the final level of luigis mansion
Yes there will be a luigis mansion 2. Its called the elictric boogaloo
probably in the laundry room
unfortunatly, you have to beat the game 15 times. then go to options menu and choose god mode.
Suck up a Shadow Ghost until it becomes a ball and shoot it at the real ghost then you can suck it up!
you dont get luigi mansion in the day
Go to VidoEmo.com. there are plenty walkthroughs there.
poltergust 3000
no luigis mansion is on gamecube buy 1 they r cheap 30 $ or so