I’m presuming this is a Catholic church?
It’s okay for priests, or even in some circumstances other Catholics, to lay hands on and pray for each other, whether or not it’s a charismatic prayer group/ service or some other type. My personal preference is for a reliable priest or deacon to be present when having these prayer groups or services, so people don’t start doing things that only priests or deacons should do, but given that we have a clergy shortage, many churches allow these groups to meet on their own, and that may be okay if the priest has a general idea of what’s going on and there’s some trustworthy layperson in charge of the group.
Catholics have had charismatic services (called Catholic Charismatic Renewal or CCR) for about the last 50 years and the Vatican approves of this so it’s not new and not an issue. Sometimes Catholics do get slain in the spirit when attending these, and there are a number of Hispanic people who attend in my area, although there are plenty of people of other backgrounds there as well. There are many other Catholics who are not comfortable attending these groups/ services, and the answer for them is simply, don’t attend, and be tolerant towards the people who do spritually benefit from Catholic charismatic prayer.
They likely black out the windows because they want privacy to pray in an expressive manner and don’t want people gawping at them through the windows.
My biggest worry right now would be if you have COVID in your area, these folks aren’t practicing social distancing - they really shouldn’t be touching each other if they aren’t living in the same household.
