About a month ago we went to replace the bulb in my sons closet and it wouldn't work.. so we never got aorund of calling a electrician yet.. thinking it might be the wires where you put in the bulbs... well the light bulb was out in my laundry room last night so I replaced it and went to cut it on but no light there.. so my brother was thinking it could be the switch.. well the switch does look a little loose then others... where you cut the light off and on...

So I am guessing your question is why the light fixture(s) are not working and how to determine what the reason is and how to repair.

The problem(s) can be one or more of several reasons:

Defective new lamps (light bulb), try lamp in working socket.

Hot contact eyelet at bottom of lamp socket is pushed down and not making contact with bottom contact on lamp. Be sure power is off and use a plastic tool to pull contact up a fraction of an inch. This will insure the hot contact in the socket is making contact with the bottom of the lamp.

Defective wall switch(s),replace switch(s).

Power in circuit(s) is off due to some other reason or problem in circuit(s), such as a loose connection or tripped breaker. Troubleshoot circuit to be sure power is at each switch.

Note:
A "loose switch" should only mean that the two screws that attach the switch to the outlet box are loose, however , these screws only support the switch, and have no effect on the electrical operation of the switch.

Also, I need to comment on the light fixture in the closet, just to be sure the correct light fixture is being used. This light fixture should be the type with some sort of globe or cover to enclose the lamp. Open lamps are not allowed in closets fully exposed as this can be a fire hazard. If someone were to leave the light on, and the bulb is close to clothing or other combustibles, there is a potential of starting a fire. Just wanted to pass this on.