Hello! I have a friend who has seen shadow people since she was a child, so I've been doing a lot of research on them and how to get rid of them.

There are tons of ways to ward off shadow people. You could create sachets with rosemary to put on bedside tables or under pillows. These will help keep the shadow people away from where your kids sleep. They could even be placed in bags or purses! 

You might also want to seek out some grounding crystals. Onyx is the strongest, and dark entities tend to avoid it as it can trap them. 

Burning a white candle before bedtime can also help! Any sort of light will help chase away shadow people as they absolutely hate it.

Thinking positive thoughts would also help, but I know how difficult that is to do when you're young, it's dark, and you're very scared.

As for cleansing your house, which I suggest you do, burning sage is one of the best ways to drive out any sort of malevolent spirit. I personally like sage sticks! 

You mentioned your son has special needs, so this method may not work for you, but you can take pots and/or pans and bang them as you walk through the house while telling the spirits to begone can be fun and as well as powerful for cleansing. Doing it together would add to the power, and bonus points if the pot(s) are old, well-used, and well-loved.

Finally, and I'm assuming you are a woman, you are the matriarch of this house. You have a lot of innate power already, and confidently telling the spirits to go away, this is your home not theirs would be extremely powerful. If you have a spouse, they could also add to your power if present and willing.

If you feel this isn't enough, using a straw broom and sweeping the house while visualizing sweeping away unwanted guests is another good method. I like this way because I'm a visual person. 

Finally, once they are banished, make sure to salt all thresholds (windows, doorways, fireplace, etc.) to make sure they don't return.

I hope this was of some help!!!