Candles are an absolute no-no.
That's not true - candles need proper care to make them safe, but they can be very safe and very useful. People have just forgotten how to use them properly.
Have them in a solid holder where they won't wobble, if the holder is too big, dribble a little melted wax from the top of the candle when you light it into the holder and hold the candle straight in that for a minute until it rehardens.
Make sure the holder is placed on a solid, secure place which is not in a draught and which is out of the reach of DCs. Where it will not burn anything above it (like a shelf etc). And where it is not likely to be knocked or cause a burn on someone walking past or doing a job nearby.
NEVER leave a burning candle unattended. So light them in the room you will be in for a few hours, not to keep a light on the stairs for traffic.
Tealights can be easier to make secure as they are lower. But there are plenty of proper candlesticks, lanterns and other holders to keep all sorts of candles secure and safe. Some just hold the candle base securely, some completely enclose the flame as well (but you still need to let oxygen in to allow it to burn).
They are very useful in the middle of a kitchen table when people are sitting to eat or read or do homework. (But not for a boisterous game). They are very useful in a sitting room on a mantle (especially if there is a mirror to reflect the light and magnify it, at a safe distance from the flame) if you are sitting in there for the evening.
And no one is EVER allowed to play with the flame.
They tend to last a reasonably long time and don't need batteries etc - which can be handy if the power is out a lot or you have a single but long duration outtage over a few days.
But they are something to have for their purpose, alongside battery/windup/solar-powered torches or lamps as well. So headtorches for moving around, a camping lantern in the hall/at the top of the stairs, a bright lantern for cooking purposes are all important to have as well. And another way to boost the light of a torch is to wrap a headtorch around a full plastic bottle of water and point the light through the water - well known camping hack so could be useful for that kitchen table use instead of candles.