Consider using Nems suggestion of an ID for each dynamic light plus a switch that is set by the action of each dynamic light that tells whether its range reaches the player (light_1_withinrange = 1, or 0 when not within range). The player action the simply keeps a graded score stealth_trigger = light_1_withinrange + light_2_withinrange + light_3_withinrange + ...

Then when the stealth_trigger is larger than 0 the player is in stealth mode ...

(var names could be shorter, they are long here just for clarity)