Even the most conscientious cleaner is likely to miss some of the places around the home that harbor germs. Though many of them can’t obviously be spotted (mold in your walls, for example), some are hiding in plain sight: things like door handles and kitchen sponges are germ magnets.

Generally, staying on top of these germ hotspots isn’t difficult, especially if you make it part of your weekly cleaning routine.

Knobs, switches and handles

Germs love hard, non-porous surfaces such as door handles and light switches. Just consider how many times a day you open a door or turn on a light and that each touch has the potential to spread germs. Similarly, the buttons and knobs on cookers and microwaves are susceptible to harboring germs.

It’s simple to clean handles and switches—either dampen a cloth with soap and water or wipe down with a solution of equal parts water and distilled white vinegar. For solid brass or copper handles, take a lemon, cut it in half and spread salt over it. Then apply the lemon to the handle. This will not only sanitize the handle, but remove tarnish as well. Make washing handles part of your regular cleaning routine.

Have you ever considered an air purifier to help keep your home free from viruses?

Stove dials are especially prone to germs, with the risk that mold can find a home there. If the knobs pop off, soak them in a 50-50 solution of water and white vinegar for 20 minutes. If they aren’t removable, give them a good wipe down with the distilled vinegar solution, making sure to get into the crevices.

Mold in places you can’t see

Exposure to mold can cause headaches and nausea and even lead to serious health conditions. Mold is fond of moist conditions, especially where there is a lack of ventilation. This means it can crop up all over the place: behind sinks, in fridges, around window frames, in the drywall in the basement.

It’s important to be alert to possible breeding grounds and to check them regularly. If you do find an outbreak of mold, scrub it off, ideally using a specialty mold cleaner (to avoid contamination from chemicals or mold, wear gloves and a face mask). A big outbreak or one that is hard to get to (in the walls, for example), may require professional assistance.

The best way to avoid problems with mold is to make sure rooms are well ventilated, especially the bathroom. Use an extractor fan anytime you take a bath or shower. Look for leaks in pipes and taps and fix them. Make sure to regularly wipe down surfaces that become damp (bathroom tiles are a classic case).

An air purifier can also help in the battle against mold. The germs spread through the air as spores, and a purifier will help to capture and prevent them from spreading. Make sure the unit is powerful enough for the size of the room by checking its Clean Air Delivery Rate (CADR) and frequency of air exchange.

One place that is a notorious breeding ground for mold and bacteria is an old window air conditioning units. By their very nature, air conditioners are moist places—an environment that germs like. The bad news is that there isn’t much you can do to prevent contamination and they are almost certainly too difficult to clean. Unfortunately, if a unit has become a breeding ground, the best remedy is to replace it.

Kitchen sinks, sponges and dishcloths

Despite the fact that it may look clean, the humble kitchen sponge can be one of the dirtiest things in the home when it comes to germs. Fortunately, it’s easy to disinfect a sponge—putting it in the microwave for a minute or running it through the dishwasher should take care of most germs. You can also soak it in an oxygen bleach solution for 30 minutes for similar results, or failing that, give it a good rinse with soap and water between uses.

Make sure to switch out sponges regularly (not just when they look gross) and while you’re at it, keep an eye on your dishcloths. If in continual use, they should be changed every couple of days. Wash them on a hot water cycle to help kill germs. Avoid using sponges for picking up meat (use a paper towel instead).

The kitchen sink is another place that can harbor nasty germs (it’s a moist area that sees a lot of food particles, after all). A natural cleaner such as white vinegar is great for disinfecting stainless steel and porcelain sinks. Simply spray down the sink with vinegar and wipe clean.

If you have a garbage disposal (yes, another possible germ fest), simply pour in baking soda with an equal amount of white vinegar. After a few minutes, rinse with running warm water.

It’s easy to maintain your sink. Try not to leave dirty dishes in it for long and spray with vinegar after each use, remembering to wipe dry with a cloth or paper towel.

Kids’ toys

So, children and germs might go together like peas and carrots, but how often do their toys get a good clean? It’s not just the likes of cold and flu microbes that can get on toys, but they can be covered by toxic dust and other allergens brought or wafted in from outside.

You want to make sure not to use harsh cleaners—anything you’d use on or around your child, such as baby wipes or gentle kids’ soap, are good to go. For soft toys, check whether they have labels with washing instructions. Unless it says otherwise, or the toy is delicate, then it can go in the washing machine. Place in a pillowcase or laundry bag, and run on a delicate cycle, using baby detergent. Dry on a low heat.

Plastic toys, such as Legos, can be soaked in warm water with a splash of dish soap for 10 minutes. Rinse under a tap and air dry. You can use the same procedure on bath toys. However, if you squeeze a rubber duck and black flakes come out, then you need to throw it away as it’s really gone moldy. For convenience, you can also put toys in a dishwasher on a cool/delicate cycle.

Anything that can’t be immersed in water can either be vacuumed (if it’s fluffy), or wiped down with disinfectant wipes. As an alternative, make a baking soda paste (a drop of water mixed in with a tablespoon of baking soda) for wiping over hard surfaces. Clean off with a damp cloth.

All kinds of electronics

Our hands are all over our gadgets and computers, making them some of the germiest places around. Keyboards, touchscreens, phones, game controllers and remote controls all have the power to make us sick—and require regular cleaning. To tackle keyboards, use a can of compressed air to remove bits of dust and crumbs. Then dab a cotton swab in rubbing alcohol and carefully wipe the keys.

For video game controls and remotes, remove batteries, and then shake upside down to remove any debris (you can also give it a blast with some compressed air as well). Scrub into the gaps and crevices with a (clean) toothbrush. To sanitize, mix up a solution of rubbing alcohol and water and apply with a damp cloth.

Follow the manufacturer’s recommendations when it comes to cleaning screens, as chemicals may damage them and void warranties.