If you want the ghost to always be in the same room as the player (instead of approaching from across the map) then instead of using "let way be the best route..." you can just move the Ghost to wherever the player is.
"Ghost Follows Around"
Entrance is a room.
Kitchen is north of Entrance.
Bathroom is south of Entrance.
Ghost is a man in Kitchen.
Ghost can be following.
Every turn while player is in Kitchen:
if Ghost is not following:
say "The ghost starts following you!";
now Ghost is following.
Every turn while Ghost is following:
if Ghost is not in the location:
say "The ghost follows you in!";
now Ghost is in the location.
Every turn while player is in Bathroom:
if ghost is following:
say "The ghost disappears!";
now Ghost is not following;
now Ghost is in Kitchen.
When the ghost is "following," it just pops up in the room whenever the player moves. ("Now Ghost is in the location" means "move the ghost to the room where the player is.) We make this stop by saying that the ghost is not following anymore when the player is in the bathroom.
It's probably a good idea to include a message like "The ghost follows you in!" because otherwise the player won't know the ghost has followed her until she tries >LOOK again. Of course, when the player gets to the bathroom, two different messages will be triggered:
Entrance
The ghost follows you in!
>s
Bathroom
The ghost follows you in!
The ghost disappears!
If you don't want this to happen, you can insert the "ghost disappears" rule into the "ghost follows" rule:
Every turn while Ghost is following:
if location is Bathroom:
say "The ghost disappears!";
now Ghost is not following;
now Ghost is in Kitchen;
otherwise if Ghost is not in the location:
say "The ghost follows you in!";
now Ghost is in the location.
Now only one message will show up in either situation.