There is a common misconception that if a swift is found on the floor it probably has been grounded and is unable to take off but will be healthy. This is untrue Swifts can take off from the floor, you can find a few YouTube videos if you don't believe me. the only reason a swift would be unable to take off is if the area its landed in has damaged or dampened it wings,
its injured, its weak from starvation or illness or its suffered concussion.
What to do if you find a swift:
Put it in a safe box, for the best environment for them place a towel
or piece of fabric on one side so it's hanging as they cling to the sides
Do not give water or food these birds need specific feed
as they are strictly insectivores.
Find a rehab who have experience with Swifts as they will
not thrive in captivity with inexperienced handlers.
Please DO NOT throw the bird in the air as your sometimes instructed to
a bird should never be forceably launched into the air.