Due to possible failure, Kidde has recalled certain smoke detectors it manufactured.  Does your smoke detector look like this?

The defective detectors are these:

If you have one of these, the US Product Safety Commission recommends you “should remove the alarm from the wall/ceiling and visually inspect it through the opening on the side of the alarm for the presence of a yellow cap. Consumers should not attempt to take apart the alarm, open the casing, or otherwise remove the yellow cap themselves.”

The yellow cap indicates the alarm may not function.  Don’t be lulled into false security.  A Plus Electric is standing by to help.  Call 517-529-0000 and receive an estimate on a reliable replacement.