The signal strength fluctuating can be cause by a few things but the main culprit is likely to be Alpha and Delta waves. Your brain is made up of billions of brain cells called neurons, which use electricity to communicate with each other. The combination of millions of neurons sending signals at once produces an enormous amount of electrical activity in the brain, the resulting magnetic field can cause disruptions in other electrical signals in the vicinity.
To resolve this potential issue the best 'fix' to use in a home environment is to have electromagnetic impairment devices available for anyone in the area of the equipment.
electromagnetic impairment device example
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Hope that helps.
To be safe it would be best to make anyone entering your house to wear one as it is better to be safe than sorry.