Lumo

Very late in the game, when exploring the posh looking castle parts with the tiled floors, you'll eventually progress the the story to find yourself in a huge PacMan maze, complete with four ghosts chasing you. This has to be passed to progress the story, so don't worry about finding it. You'll come this way eventually as you progress.

The ghosts in the maze move marginally faster than you, and if they get too close they'll follow your exact route around every corner.

As soon as you have control of your character, head straight for one of the maze corners, where you'll find a full wand charge. You can tell where the off-street ghosts are thanks to the throbbing on screen arrows which appear - you cannot touch one at all, or it will void the achievement.

Get straight to the corner and collect the charge. Now hunt a ghost down, and when you get reasonably close (don't risk death, the range is pretty good), hold down to capture the ghost in your stream. Now, walk back to the centre of the maze with the ghost in tow, where it will be sucked into the spectral containment unit completely nondescript trap.

The second you regain control, head straight out and do the same. The more you capture, the easier it gets. The charges do respawn, buy not very quickly, so alternating corners is a good option. Once the final host is in the trap, the achievement will pop!

Be sure to exit via the left portal, so you can collect a cassette tape and find the hidden fire station picture, which both go towards other achievements.