Assuming a Moen, there is a plastic cap in the center of the handle. Pry it out with a thin blade and see if the screw is still in there. If so, just put the handle back on the valve stem, tighten the screw and align Ann snap the cap back on.
They do that when the hidden screw comes loose...
Sent from my iPhone using Airstream Forums
'The Silver HamShack' (2007 International 22FB CCD 75th Aniversary model)
Multiple Yaesu Radios inside and many antennae sprouting from roof, ProPride hitch
2012 shortbed crewcab 4x4 Toyota Taco TV with more antennae on it