I Give Up!

I give up! We have three smoke/carbon monoxide alarms in the living areas of our house. They are all hard-wired into the house and all connected to each other somehow. AND...they all keep going off at random times and for no reason at all!!! Ok, so they beep a few times, and then they're done until tomorrow. Big deal. But it always seems to be in the middle of the night. And I'm sleeping. So it's not OK. And it IS a big deal. We've tried it all. We've replaced all the batteries multiple times, rotated them, and cleaned them out with pressurized air to get rid of all the dust. Yes, I am whining. But I'm allowed. :) I'm now going to Google this problem and see if there is something else I can try. Any suggestions would be welcome! In the meantime, let's hope that the smoke and the CO stay away until I get the units put back into their respective outlets(they were ripped out rather violently in the middle of the night a few weeks ago. LOL).