Wired smoke alarms

We have moved into a house that has smoke alarms in all the bedrooms and upstairs on the landing also.We want to take the ones out of the bedrooms as there is a bright light on them(sometimes keeping me awake!) and also they contain some radioactive material and we feel there is no need for them present.We have disconnected the wire that they are connected to and wonder if this can be pushed back up into the attic insulation that is visible without being a fire hazzard.It is not possible to access the wires in the attic to take them up.Also one of the alarms has been disconnected and is used elsewhere in the house with a battery and while the green light is off the red light flashes like the others that are still connected and the test button works.Is this alarm ok without having the electrical connection in view of test button working and despite not having the steady green light on ?

the ones in the bedrooms just need to be joined correctly in connectors so that the circiut is still complete. just tape up the connectors and push them up into the roof. the other one that u moved and is no longer wired up should be beeping cause theres no power to it. the light thats on it is powered by the battery in d alarm itself.