SOLVED. Children’s Fantasy book. Carpenter/ handyman with magic pencil and step ladder [s]

[Jenny]

So I read this book in the 80’s and am pretty sure it’s set in America. Brother and younger sister are visiting/ staying at a relatives (I think Aunt). Aunt has someone in to do some work round the house. Boy gets suspicious as workman has step ladder which hasn’t been bought into house. Turns out handyman has a magic pencil which can change the size of things. The stepladder is also magic but I can’t remember in what way. All I can remember is when the children were on a certain step something happened. I remember the children shrank themselves at one point but then had difficulty getting back to the right size as they were too small to lift the pencil and the stepladder was shrunk at some point and a crayfish had it in its claw

[Kris]

Jenny, is this a children's picture book or novel? (I added the genre "fantasy" to the topic header.)

[Rainbowheart]

Mostly Magic

[STU]

Mostly Magic
Agreed. Mostly Magic by Ruth Chew.
The stepladder shrinks when folded up and has some kind of transportation property when standing on the top steps.

[Jenny]

Thank you both, that’s the one

[Rainbowheart]

Welcome, glad to help out!