and was the result positive or negative?
I believe you're talking about a Fire alarm pull station which is the red wall mounted device you normally see in buildings. When someone pulls down on the device it activates an alarm to a fire dispatcher. Fire units will respond to the box and deactivate it. This is usually done by a Special tool. In my state (MA) coded stations were discontinued by the 90s. I'm sure they're still used in some districts.
Alpha radiation can't penetrate more than a few centimetres of air, if that. Your skin is more than enough protection against it. Ionisation is indeed bad for you, but alpha radiation will only ionise body tissue if you actually eat or breathe in the source. Otherwise, alpha particles can't get far enough to do any damage. Incidentally, gamma radiation, which will go through a lot of material before doing anything, is the most dangerous radiation outside the body, but the safest inside, as chances are it will go straight through the body before doing any damage. Alpha radiation is very dangerous inside the body, but completely harmless outside it. I would be rather surprised if the alpha radiation from your smoke detector even got through the plastic shielding. In short, it's entirely safe.
