Hy AM,
Here is a practical design:
As you are in the United States, component availability will not be a problem: Mouser, Digikey, etc
NOTES
(1) R15 is selected for the desired LED current.
(2) R16 speeds the LED turn off
(3) All non polarized capacitors are ceramic 25V or more, with X7R dielectric. Small cased ceramic capacitors are not suitable.
(4) The LM555 timer chip is simply used as a gate driver
(5) R17 is a gate stopper to reduce the chance of the MOSFET oscillating at a high frequencies. R17 should be soldered directly to the PMOSFER gate pin. R17 plays no role in the fundamental function of the circit.
(6) All capacitors play no part in the fundamental functioning of the circuit. Instead the capcitors are decouplers to ensure that the circuit operates as intended.
(7) The NMOSFET is a low gate drive type which allows it to be turned on by low voltages (see data sheet)
(8) The NMOSFET is housed in a TO220 thru hole case for easy handling.
DATA SHEETS & SOURCES
(1) NXP PSMN017-30PL
**broken link removed**
(2) LM555
https://www.ti.com/lit/ds/symlink/lm555.pdf