Do you have a smoke or carbon monoxide detector that continues to beep even after you've changed the batteries?
Smoke and CO2 detectors don't last forever. They only have an approximate 10 year life span. After that the detector component begins to malfunction and the detector will chirp every few seconds, letting the homeowner know that something's not right.
Some manufacturers have a specific chirp for low battery and one for bad detector. Check with your specific manufacturer and model to verify this.
A new replacement is the only option here. This is also a good time to check all the other detectors in the house. They are usually installed at the same time. If one is bad, it likely won't be long before the others go too. Save money by buying them in bulk and replace them all at once.
They are literally life savers.
Professional Handyman can help with the installation.