Book read in elementry school 2nd-5th grade child locked in museum

There was a book that I had to read when in school about a child locked in a museum, there was a fountain with coins in it and he got money out to eat.

It was in the late 80's early 90's

It sounds a little like From the Mixed-Up Files of Mrs. Basil E. Frankweiler, but it was two children and they had actually run away from home and were living in the museum. They did dip into the fountains for money. It's a wonderful book and even if it's not the one you're looking for, I recommend it! :-)

That's it!! I remember now, it's been a long time since I read it ;)

Thanks!!!!!

You're welcome. Hope you enjoy your reread!