In the play, The Curious Savage, the radio won't work because Mrs. Paddy stole the radio tubes. They show up though, in the last act as they tumble out of a shoe box. Now, where in this day and age, do we find radio tubes and if I found some, I'd be afraid they would break. What can we use as a substitute?

If you contact a ham radio operator they should be able to get you all the radio tubes you could ever need. You can go to www.arrl.org  and search for a club in your area. My husband is a ham and our house is over run with radio tubes. He literally has boxes and boxes of them. He even turned a few into Christmas ornaments. I asked him what they would cost. He said most of them should cost pennies. Also, they are far more sturdy then you might think.  If you use a clear packing tape on them they will be a little less breakable.