There are different types of electronic pest repellers. The little ones from Home Depot simply do not have enough power. I use the large ones, made by Steren, which look like small loudspeakers in my house in rural Mexico. In the past, I posted a link; too lazy tonight. Google is your friend.
Their figures estimate my 2,850 square foot house needed 3. Scorpions and mice and lizards carried on happily until I had 8 repellers in there.
Now, I have very few scorpions, ditto for mice and rats. We once found a large rate behind the fireplace. He just sat there, trembling, couldn't move. Not wanting blood and guts all over the floor, I put him in a bucket and tossed him out in the field. Big rats do not sit there and let you put them in a bucket.
And, one day a lizard came running into the house through an open front door. About five feet from the repeller, he froze and could not move. I took my shoe and dispatched him, My builder said he had previously found one dead in the exact same location.
I do not want to advertise for Steren. If you can find another source, go for it, and let us know. But, you need a LOT of power to get any results.