The forest Ghost house is one of the easiest ghost houses your ever going to find. At first it begins very compact as you wind your way through the corridor and then through the door at the end. After that there is a simple area which is guarded with flying ghosts. Now the temptation is to get the flying boxes and indeed if you do you can collect a feather or sunflower but BEWARE! the ghosts tend to swarm round you too fast and result in you getting hit. My advice is to leave them. Now the powerpack is resting on an easy to reach ledge but DO NOT jump on it yet... first continue going past the yellow door and into a small area with a line of coins above it. As long as you collect at least one coin then it means the level is completeable. NOW you can jump on the powerpack, turning all the coins into blocks, and travel through the silver door.
Now this is the easy bit, just continue along the corridor but when you see the first yellow door, don't enter it. If you do it will just lead you out of the ghost house without any freebies! Continue past it then open the next yellow door you will see. It is the same exit but it has a cute little moon resting on the floor. The moon will give you an extra three lives! Then cut the tape and you've finished. TA DA!