Using a transistor as a switch
As already noted, the direct connection of a NPN BJT (or N-channel Mosfet) in high-side configuration is not suitable (emitter follower no saturates with equal voltages Vb and Vc). A proper driver is required. For example these ones on figure below (B, instead uses a PNP):

(A) Input Low -> load On; Input High -> Load Off

(B) Input Low -> load Off; Input High -> Load On

The problem with (A) is the initial state under power-on or reset by watchdog activation. Maybe, in some application, can be a bonus.