I removed the alpha source from a smoke detector. The source itself is on a
gold colored metal foil attached to a sheet metal bracket that turned out to be
handy for handling. It was useful as an energy calibration point in an alpha
spectrometer.
I am not an expert, but as I understand it the material is firmly attached to
the foil and does not come off easily. However, I would still avoid touching
the foil and teach students to treat it with some respect.