Carbon monoxide detectors are recommended outside of every sleeping area and on every floor in the home. They should not be placed within five feet of any cooking or open flame appliances such as furnaces, stoves, and fireplaces. They are recommended to be in every room that has a gas fired appliance. They are recommended to be replaced every 10 years and tested monthly.
Most experts recommend keeping your house between 40% (in the winter) and 60% (in the summer) relative humidity. Particularly in the summer, try to keep the relative humidity below 60% and definitely below 65% as above that microbial growth occurs and condensation may occur. Use a Hygrometer to determine humidity levels-they can be purchased for as little as $5. Use, fans, a dehumidifier, and air conditioners to reduce humidity levels. https://qualityhomeinspections.org/ Quality Home Inspections 519 383 7072
A water leak alarm placed near your sump pump or the bottom of your water heater will sound an alarm when water touches the bottom of it. If your sump pump stops working or your water heater starts leaking it could save you thousands of dollars by catching a problem early. They are sold at big box stores and online.
Wish your bathroom fan would automatically turn off when the shower humidity was removed? It exists and is a quick install by an electrician. It can be controlled by timer or humidity.