If you find a bat in your house, stay calm, don’t create a fuss, and don’t scare the bat, yourself or other people in the house. Remember that bats are timid, nocturnal creatures that will reliably go well out of their way to avoid confrontations with situations and creatures that might harm them, like humans. Even if they are being chased, and even if they have rabies, they are rarely aggressive towards humans.
Also remember, if a bat is flying around inside a room, it will appear to dart in and out, up and down, quickly, to avoid hitting walls or objects in the room. It is important to understand that these quick flying maneuvers are much more likely to be from avoiding flying into objects than from trying to “attack” a human.
It is possible that if you attempt to handle a bat, it might try to bite you, either out of fear or self-defense. Do not handle bats without wearing gloves. However, in allowing a bat to simply leave your house on their own, there will be no need to directly handle the bat.
First, you’ll want to seal up other parts of your house, doors, windows, fireplaces, etc, in the room where the bat is located. This will prevent the bat from flying into other areas of your house. Be sure to leave OPEN the door or window that the bat flew into in the first place.
If you can leave the door or window open and the bat unattended, especially until after dusk, the bat may simply fly back out of the door or window that they flew into in the first place. If you cannot leave the bat and room unattended, you might want to gently push the bat with a broom or long stick from the ceiling or wall into flying, and wait for it to fly out of the room. Chasing the bat, swatting at the bat and yelling at the bat will likely just further confuse the bat, making it more difficult for it to find its own way out of your house. It is better to simply allow the bat to leave your house, then to try to force or scare or threaten the bat into leaving.